The following is the list of games that are available via Apt-Get:
20,000 Light Years Into Space
3D Chess
4-Digit
Abuse
ACM (Aliens: Colonial Marines)
Airstrike
Allegro demo
Angry Drunken Dwarves
Atom
Atomic Tanks
Battle for Wesnoth
Battle Tanks
Battleball
Beneath a Steel Sky
Blob Wars: Metal Blob Solid
BlockOut 2
DeSmuME
Feeding Frenzy
Flare
FreeCiv
FreeCraft
FreeDink
Freesweep
Funny Boat
Fuse
Galaga
Galaga: Hyperspace
GNU Shogi
Hexxagon
KETM (Kill Everything That Moves)
Lincity
Little Crane
Mancala
Mednafen
Micropolis
Minecraft: Pi Edition
Monsterz
NetHack
OpenTTD
Overgod
PrBoom
Pydance
Rafkill
Snake4
Sopwith
SpaceZero
Spout
Stax
Stella
SuperTux
Tagua
Teddy
Tetzle
TINT
Triplane
Vavoom
XSoldier
Xtron
YahtzeeSharp