The theme generator picked 'Kittens' for me. I decided to use a pre-made swarm algorithm to make a game with this.
There is a swarm of 100 kittens which you should guide to the goal (brighter square) by placing a fish. You can only place a fish when the already placed fish disappeared. The spikes kill the kittens. 50 have to survive and reach the goal to win.

No sound and only one level.

With Windows start Kittens.exe. Kittens.py should run with Linux, if you have pygame installed.