Algodoo

click on the molecules in the box and copy and paste them.
black molecule - tough stone
gray molecule - stone
red molecule - heart (defines a cell instead of an asteroid or planet)
green molecule - acid
yellow molecule - lightning molecule (kills itself)
blue molecule - strong molecule (attracts more)
white molecule - Repelling Molecule (repells things)
Magenta molecule - cutter molecule (slices things) (when copying, use a select box instead of clicking!)
Membrane Molecule - connects to other skin molecules (may have to do manually)

Sad Story: Tried to add healers and damagers to the sim. its a shame i couldn't get them working.

Ghosts: a delightful litte surprise when working. they don't do anything, they don't even collide. all they are is a fun
little emotion filled buddy.