This game is being developed on the Unity platform. The C# code is in Assets -> Scripts.
The goal is to take over your opponents slime by exploding onto their squares. You win once all your opponents are eliminated. The rules are simple. You can only place slime on an empty square or on one you "own" (already have slime in). Each square has a limit of the number of squares adjacent to it (corners: 2, sides: 3, middle: 4). Once a square reaches its limit, it explodes adding one slime to each adjacent square and taking over any opponent's squares. Checkout some example gameplay here.
Chesslime is currently available for Windows, Linux and as an Android app here. Eventually I plan to get real multiplayer working and publish it on Google Play and on the iOS app store.