A simple app with clever gameplay. A collection of eight 2D games and two 3D games that are well implemented, supporting human vs human or human vs AI (with difficulty levels).

The key feature differentiating this from many other games is the addition of different topological options. The exact options vary between games, but most include a torus and a Klein bottle.

The special thanks section include a mention of the National Science Foundation, and to be honest, the presentation of the app certainly has an… academic feel to it. But what it lacks in visual style it makes up for in speed, cleanness, and just being very to-the-point.

As a final note, it is available on Android, iOS, Windows and macOS (I tried the Android version), is free, and has no ads.

Good things

• Many games.
• Many options.
• Actual 3D.
• Localized in 15 languages.
• Quick AI.
• Small and quick to load.

Bad things

• Not particularly polished (but apparently reliable and robust).

Game features missing from Tic-tac-toe Collection

• Topology options.
• 3D tic-tac-toe.
• Other games quite unlike tic-tac-toe.

App features missing from Tic-tac-toe Collection

• Localization.
• Sound effects.