I originally made these to be added to NetBSD (but the few i talked with preferred to have games in the repositories rather than in /usr/games itself).
These include:
Jewels (A game with a gameplay kinda similiar to that of Tetris, NOT my invention)
Sudoku
Mines (Minesweeper)
Reversi
Checkers
Battleship
SOS
Rabbithole (A maze-exploring game where you have to gather items from all around the maze rather reaching an end,the idea maybe mine)
Pipes (Same as the famous Pipe Mania, unplayable on the environments that don't support the line characters)