In Blocks you have the target to set blocks in the opponent players way and not moving yourself into them. Thats all. It's funny.
Blocks II is written in QuickBasic. This version has no great graphics, no sound and is only for two (2) players. The source code is included.
Unfortunately Blocks II must run in 320x240 fullscreen mode, so look what display you have or use the dosbox emulator.
Blocks III is written in C/C++. It has a cpu vs. cpu, a single player and a two player mode. And it has "great" music and a little bit more graphics than blocks II. The source code is included, too.
Blocks II and III (339kb)