Trap A Cat

This game was suggested by Uhclem: Circle the Cat.

It meets my criteria for the perfect game: takes about a minute, quick to learn, and utterly addictive. You can tell yourself you'll just play one...but you won't. It's a cute variation on Piet Hein's game Hex.

The goal is to trap the cat by clicking the light green circles. I played it about 20 times before I trapped that cat.