Short version:
You can automatically download and install 54, of what I think, are the most decent Linux games, via an automated script.
System --> Commodore OS --> Free Games Installer
The list of games is provided below. These games seem to play well with the system.
Here is a forum post on the best way to play the games.
viewtopic.php?t=11
If you want to install various games individually, you can go to the Software Installer Games Category.
System --> Commodore OS --> Software Installer (Games category)
Hurrican, is a game that pays homage to the famous Turrican games, and is ready to play on the base Commodore OS install.
Click the Commodore Icon on the dock to take you to the Systems folder and navigate:
Linux / Hurrican
Enjoy.
Long version:
Version 1 of COS had a number of Linux games included. IIRC there were some games on the DVD 1 base install, and then you could install more with the second DVD dubbed Commodore OS Extras. All the games were nicely categorised in the Game menu under their genre. This time around, I could have included then all in the same ISO (now that it can be as big as you want), but I thought that perhaps people might prefer the base OS and apps and to optionally install the games separately. And by separately I mean all at once
. And then all dog-piled in the Games folder. 
Could I have made an optional installer for each of the games? Yes!!! And that is the plan for a future release/update. (Edit: No, all the games will come pre-installed with the ISO and will be properly categorised)
I am currently developing a unified retro Game database front end for all the different microcomputers and retro consoles which would (eventually?) include Free Linux games, Free Windows Games and Free DOS games available for download over the internet. This is what was intended to be launched from the Commodore icon in the dock, instead of a file explorer window to the retro Systems folder. (Edit: No, it won't be ready for COS3 due to schedule, there is an alternate launcher that will be used for COS3 that will be optional thereafter)
Below are a list of the games, and the individual commands to install these one by one at your leisure via the Command Line Interface(Bash shell).
Below each command is the corresponding command to uninstall the game (remove the leading #).
# A7XPG (Window can be maximised)
# Category: Action
# Pick up bonuses around the screen in your spaceship whilst being chased by aliens.
sudo apt install -y a7xpg
#sudo apt remove -y a7xpg
# Armagetron Advanced
# Category: Action
# A 3D Tron light cycle game.
sudo apt install -y armagetronad
#sudo apt remove -y armagetronad
# Barrage (Full screen automatically)
# Category: 2D Shoot-em-up
# Use your mouse cursor to aim your cannon at enemy tanks and troops.
sudo apt install -y barrage
#sudo apt remove -y barrage
# Beneath a Steel Sky (Window can be maximised)
# Category: Adventure
# A classic SciFi 2D point and click game. (ScummVM)
sudo apt install -y beneath-a-steel-sky
#sudo apt remove -y beneath-a-steel-sky
# Cave Express (Full screen automatically)
# Category: Platformer
# A classic 2D platformer with physics-based gameplay and dozens of levels. Master your pedal-powered flying machine
# to pick up packages from your cave-dwelling clients and drop them off at the collection point.
sudo apt install -y caveexpress
#sudo apt remove -y caveexpress
# Ceferino (Launches as fixed window, must run ceferinosetup from CLI to go full screen. Select "Pantalla completa : Si" "Salir y guardar")
# Category: Action
# A game similar to Super Pang.
sudo apt install -y ceferino
#sudo apt remove -y ceferino
# Chromium B.S.U. (Launches as fixed window, Full screen from menu may fail)
# Category: 2D Shoot-em-up
# A fast paced high action, vertical scrolling space shooter, controlled by mouse.
sudo apt install -y chromium-bsu
#sudo apt remove -y chromium-bsu
# Criticalmass
# Category: 2D Shoot-em-up
# A vertical shooter similar to Galaga but controlled by your mouse.
sudo apt install -y criticalmass
#sudo apt remove -y criticalmass
# Drascula: The Vampire Strikes Back
# Category: Adventure
# A comedic 2D point and click adventure. Uses SCUMMVM with voice samples and music.
sudo apt install -y drascula
#sudo apt remove -y drascula
# Extreme Tux Racer (Launches in window. Can be set to Full screen)
# Category: Racing
# Help Tux navigate a downhill slope and stay within the flags in this 3D game.
sudo apt install -y extremetuxracer
#sudo apt install -y extremetuxracer
# Frozen Bubble (Fixed window)
# Category: Puzzle
# A game where you shoot different coloured bubbles to match bubbles and clear the level.
sudo apt install -y frozen-bubble
#sudo apt remove -y frozen-bubble
# Freedroid (Fixed window)
# Category: 2D Shoot-em-up
# A perfect port of the fantastic C64 game Paradroid. WASD keys to move, Mouse to aim, Left Button to shoot, and Right Button to challenge droids.
sudo apt install -y freedroid
#sudo apt remove -y freedroid
# Emilia Pinball (Launches in window. Can be set to Full Screen)
# Category: Action
# Play Pinball from a selection of 4 differently themed table designs.
sudo apt install -y pinball
#sudo apt remove -y pinball
sudo apt install -y pinball-table-gnu
#sudo apt remove -y pinball-table-gnu
sudo apt install -y pinball-table-hurd
#sudo apt remove -y pinball-table-hurd
# FooBillard Plus (Didn't auto install due to a typo. To install use command below) (Launches in window. Can be set to Full Screen)
# Category: Action
# A 3D Billiards game. Requires a decent PC.
sudo apt install -y foobillardplus
#sudo apt remove -y foobillardplus
# GLTron (Fixed Window)
# Category: Action
# A 3D Tron light cycle game.
sudo apt install -y gltron
#sudo apt remove -y gltron
# GunRoar (Fixed Window)
# Category: 2D Shoot-em-up
# A 2D Vector based shoot'em up. Use WASD to control your gunship, mouse to aim, and left and right buttons for narrow and wide shots.
sudo apt install -y gunroar
#sudo apt remove -y gunroar
# Holotz's Castle (Launches in window. Can be set to Full Screen) (Exit other than menu may crash system)
# Category: Platform
# An odd 2D old school platform game where you avoid enemies and collect keys on the screen to find the exit.
sudo apt install -y holotz-castle
#sudo apt remove -y holotz-castle
# Kobo Deluxe (Launches in window. Can be set to Full Screen with ALT-Enter) (Joystick works)
# Category: 2D Shoot-em-up
# A slick 2D shoot'em up.
sudo apt install -y kobodeluxe
#sudo apt remove -y kobodeluxe
# Lure of the Temptress (Launches in window. Can be set to Full Screen with ALT-Enter)
# Category: Adventure
# A 2D point and click adventure game. ScummVM.
sudo apt install -y lure-of-the-temptress
#sudo apt remove -y lure-of-the-temptress
# M.A.R.S A Ridiculous Shooter (Launches in Window. Can be set to Full Screen.)
# Category: 2D Shoot-em-up
# A slick multi-player 2D gravity based shooter.
sudo apt install -y marsshooter
#sudo apt remove -y marsshooter
# Mine Test (Launches in Window. Window can be maximised.)
# Category: Action
# A MineCraft clone for when you really want to MineCraft. Creates a server.
sudo apt install -y minetest
#sudo apt remove -y minetest
# Moon Lander (Fixed Window)
# Category: Action
# A Lunar Lander clone with modern graphics and sound.
sudo apt install -y moon-lander
#sudo apt remove -y moon-lander
# Ucade (Window can be maximised.)
# Category: 2D Shoot-em-up
# A vector based shoot'em'up where you control a snake like ship that can shoot in all directions, and killing enemies extends your ship's tail.
sudo apt install -y mu-cade
#sudo apt remove -y mu-cade
# Neverball (Launches in window. Can be set to full screen in Settings)
# Category: Action
# A 3D ball game, where you tilt the platform to move the ball around, collecting coins before the time limit runs out to reach your goal exit.
sudo apt install -y neverball
#sudo apt remove -y neverball
# Neverputt (Launches in window. Can be set to full screen in Settings)
# Category: Sport
# A 3D mini-putt game for 1-4 players.
sudo apt install -y neverputt
#sudo apt remove -y neverputt
# Nexuiz (Launches in window. Can be set to Full Screen, but be sure to set it to your screen resolution as it exits poorly)
# Category: 3D Shoot-em-up
# A first person 3D shooter.
sudo apt install -y nexuiz
#sudo apt remove -y nexuiz
# Open Arena (Launches in window. Can be set to Full Screen)
# Category: 3D Shoot-em-up
# An online first person 3D shooter. There are enough bots to make it interesting.
sudo apt install -y openarena
#sudo apt remove -y openarena
# Open Invaders (Launches in window. Can be set to Full Screen)
# Category: 2D Shoot-em-up
# A Space Invaders clone.
sudo apt install -y open-invaders
#sudo apt remove -y open-invaders
# Parsec 47 (Launches in a window, but can be maximised)
# Category: 2D Shoot-em-up
# A fast paced 2D vector shoot-em-up.
sudo apt install -y parsec47
#sudo apt remove -y parsec47
# Pekka Kana 2 (Full screen by default)
# Category: Platform
# An impressive 2D scrolling platformer similar to Super Mario with a chicken as the main character.
sudo apt install -y pekka-kana-2
#sudo apt remove -y pekka-kana-2
# Phase 1: Free Doom (Launches in Window, but can be maximised and can be set to Full Screen)
# Category: 3D Shoot-em-up
# A 3d first person shooter with similar graphics to Doom.
sudo apt install -y freedoom
#sudo apt remove -y freedoom
# Phase 2: PRBoom-Plus Free Doom (Launches in Window, but can be maximised and can be set to Full Screen)
# Category: 3D Shoot-em-up
# A 3d first person shooter with similar graphics to Doom.
sudo apt install -y prboom-plus
#sudo apt remove -y prboom-plus
# Pingus (Launches in Window, but can be maximised and can be set to Full Screen, settings take affect after relaunch)
# Category: Puzzle
# A Lemmings clone with penguins.
sudo apt install -y pingus
#sudo apt remove -y pingus
# Plee the Bear (Launches in Window, but can be maximised and can be set to Full Screen)
# Category: Platform
# A 2D scrolling platformer.
sudo apt install -y plee-the-bear
#sudo apt remove -y plee-the-bear
# Powermanga (Launches Fullscreen)
# Category: 2D Shoot-em-up
# A 2D space shoot-em-up similar to Galaga.
sudo apt install -y powermanga
#sudo apt remove -y powermanga
# Pyracerz (Launches in the fixed window)
# Category: Racing
# A 2d race driving game similar to Super Sprint.
sudo apt install -y pyracerz
#sudo apt remove -y pyracerz
# Project Starfighter
# Category: 2D Shoot-em-up
# A 2D shooter.
sudo apt install -y starfighter
#sudo apt remove -y starfighter
# Quadrapassel (Launches in Window, but can be maximised)
# Category: Puzzle
# A game similar to Tetris.
sudo apt install -y quadrapassel
#sudo apt remove -y quadrapassel
# Rockdodger (Launches Fullscreen)
# Category: 2D Shoot-em-up
# A 2d sideways shoot-em-up scroller where your ship must dodge asteroids.
sudo apt install -y rockdodger
#sudo apt remove -y rockdodger
# SDL-Ball (Launches Fullscreen)
# Category: Action
# A Breakout/Arkanoid clone.
sudo apt install -y sdl-ball
#sudo apt remove -y sdl-ball
# ScummVM
# Seahorse Adventures (Launches as fixed window. Zoom in to play)
# Category: Platform
# A 2D scrolling platformer similar to Super Mario.
sudo apt install -y seahorse-adventures
#sudo apt remove -y seahorse-adventures
# Stunt Rally (Launches in a window, but can be maximised)
# Category: Racing
# A detailed 3D rally game. A high performance PC is recommended.
sudo apt install -y stuntrally
#sudo apt remove -y stuntrally
# SuperTux2 (Launches as a window, that can be maximised or made FullScreen)
# Category: Platform
# A 2D scrolling platformer similar to Super Mario.
sudo apt install -y supertux
#sudo apt remove -y supertux
# Super Tux Kart (Launches as a window, that can be maximised or made FullScreen)
# Category: Platform
# A Mario Kart clone featuring Tux the Linux mascot and his friends.
sudo apt install -y supertuxkart
#sudo apt remove -y supertuxkart
# Titanion (Launches in a window, but can be maximised)
# Category: 2D Shoot-em-up
# A fast paced 2D vector shoot-em-up.
sudo apt install -y titanion
#sudo apt remove -y titanion
# TORCS (Launches as a window, that can be maximised or made FullScreen)
# Category: Racing
# An impressive 3D rear view race game in a similar vein to Gran Turismo.
sudo apt install -y torcs
#sudo apt remove -y torcs
# Trackballs (Launches as FullScreen)
# Category: Puzzle
# A game where you guide a marble through a difficult terrain. A Marble Madness clone.
sudo apt install -y trackballs
#sudo apt remove -y trackballs
# Torus Trooper (Launches in a window, that can be maximised)
# Category: 2D Shoot-em-up
# A fast paced 2D vector shoot-em-up with 3D effects.
sudo apt install -y torus-trooper
#sudo apt remove -y torus-trooper
# Trigger Rally (Launches FullScreen)
# Category: Racing
# A 3D rally game.
sudo apt install -y trigger-rally
#sudo apt remove -y trigger-rally
# Tumiki Fighters (Launches in a window, that can be maximised)
# Category: 2D Shoot-em-up
# A fast paced horizontal vector shoot-em-up with innovative mechanics.
sudo apt install -y tumiki-fighters
#sudo apt remove -y tumiki-fighters
# Tux Football (Launches in a window, but can be made FullScreen)
# Category: Sport
# A vertical pitched football game.
sudo apt install -y tuxfootball
#sudo apt remove -y tuxfootball
# Val and Rick (Launches in a window, that can be maximised)
# Category: 2D Shoot-em-up
# A vertical scrolling shoot-em-up where the ship can turn in all directions and fire both bullets and bombs.
sudo apt install -y val-and-rick
#sudo apt remove -y val-and-rick
# Vectoroids (Launches FullScreen)
# Category: 2D Shoot-em-up
# A modernised remake of Asteroids.
sudo apt install -y vectoroids
#sudo apt remove -y vectoroids
