REX is a streamlined chess-like digital board game that’s easy to learn and quick to play.

The board is a compact 5×5 squares, and each player starts with only 5 pieces: two “Guards”, two “Priests” and a “King”.

Each piece has different rules for moving – essentially, they’ve able to jump 1, 2 or 3 squares – and a built-in tutorial explains every point. Even if you forget, there are hotkeys to remind you which piece is which, and where it can move.

There are multiple playing modes, including computer opponents with four levels of AI, and an option to play against a friend.

The program is a bulky download, but that’s because it’s been developed with the Unity game engine, and you’re getting some very professional features. There’s control over screen resolution, graphics quality, target monitor and hotkeys, and you get a gorgeously-rendered 3D view of the board and environment (right-click and drag to look around).

The Unity-powered 3D graphics look amazing

Gameplay seems nicely balanced. The most basic computer opponent is easy to beat, even as a novice. Play gets more complex as you try the others, but games are still over in a few minutes, typically, good news if you’ve only a little time to spare.

We noticed one or two small technical issues, including a lengthy pause on launch for no apparent reason, but overall REX was easy to learn and fun to play. If you never learned chess or don’t have the time to spend on full games, REX could be a more convenient way to fill a few minutes.

REX is available for Windows, Linux and Mac.