Algodoo

Phunlet-Friendly, simple, and it works. place this in your game, has collision layer A to set the checkpoint off, and col layer g for decoration. then, make something in your game that has App.undo in its onlaserhit/onhitbylaser/oncollide scripting. then set off the checkpoint, and do that die condition in you game!
plz comment on this thread
http://www.algodoo.com/forum/viewtopic.php?f=18&t=4011
UPDATE 1: It works better if you put in sim.running=false into your "die" object too