Ping Pong
Ping pong tables are an excellent recreation solution for anyone suffering from lack of space due to the simple fact that they can fold up for easy storage. Ping pong, or table tennis, is generally scored and has a result once a player reaches 21 points. The game can be played by two players or four players, depending on the size of your ping pong table.
Ping pong tables are relatively cheap compared to pool tables. You can find a quality pool table for two or four players that will easily fold for under $500. Ping pong paddles and ping pong balls come in accessory packs that can be purchased online for about 20$ a set.
So, for under 600$, you have a home gaming system that will store nicely and provide for hours of entertainment. Not bad! Plus, table tennis is now an Olympic sport - you may become a gold medalist someday with practice!