Do you like fast paced 2D fighting games? Some of the King of Fighters Arcade titles are on sale at the moment, about 400 points each. I'd go for The King of Fighters 02 Unlimited Match, it's pretty good, and you can check out the trial before buying it. Whoever suggested Total Miner: Forge also has the right idea, decent game and MineCraft substitute for only 240 points. Dead Pixels is also a great old school side-scrolling, zombie survival indie game for only 80 points, not to mention the wonderful, albeit uber-retro RPGs Breath of Death VII and Cthulhu Saves the World for (I believe) 240 points each.