There are eight variations:
1. 16x16, two players, no wild cards.
2. One player competing against himself (matches vs. non-matches).
3 and 4 are the same as 1 and 2 but with wild cards.
5-8 are the same as 1-4 but with a 30x30 grid.
A Game of Concentration provides examples of:
- Competitive Multiplayer: Games 1, 3, 5, and 7 have two players competing to match the most cards.
- Extra Turn: A player who matches two cards gets another turn.
- No Plot? No Problem!: It's just a card-matching game, no plot's needed.
- Puzzle Game: Finding matching images is a matter of turning over cards, then remembering what's where.
- Scoring Points: One or two points for each match, depending on the difficulty switches.
- Turn-Based Strategy: The two player games are turn-based.