Codebreaker

This one's not for stupid people. The goal of codebreaker is to guess a 3 or 4 digit number in 12 tries. The computer lets you know when your on the right track with some vague clues. In the second game, NIM, you and your opponent strategically remove blocks in an attempt to be the one to remove the last block.

The game is essentially a clone of the popular game Mastermind