Algodoo

In this game, you are a rectangle. On the left (before simulation) you have objects which will float around with no sense at all.
Your job is to kill them by bumping into them (cause a collision), and stay alive as long as you can. You have 4096 square meters to move around (excluding all objects, up to the wall).
Beware: there are small minions objects which float around at buzzling speeds and can bump on you. So beware of your health.

One point of health is restored every 60 years, which is a long period, but you are a big spacefighter.

On the box text you have everything you need to know. Happy fighting!
Updated: Now the scene actually works.