Ok I use Cracker's Mod (He said it was OK) and patched it so both stickmans are invincible.
Sorry, Windows Only.

Things StickGods Are Invincible To:
-electrocution (from water)
-liquid rubidium
-extreme temperatures
-neutrons
-cold flame
-plasma
-lava
-acid
-liquid nitrogen
-game of life elements
-hot+cold solids
-liquid nitrogen
-THE BOTTOM DEATH BOUNDARY (You could practically walk on the bottom of the window [You still die if you fall straight down])

Warning! It's not fully tested.
I'm aware that the two stickmans sometimes glitch in spawning and instantly die, I'll fix it.

Link: http://www.mediafire.com/?2ygeonrq6rt4l62
You still have to download the Dynamic Link Library files from Cracker64's Mod

Developers, Request your patch here.

Current Patches Available:
--Invincibility from particles (only particles, not effects like acid)
--Invincibility to Heat&Cool, Liquid Rubidium, the bottom death boundary

Yeah but i don't think it technically counts as a mod because i hacked it.
Note that it was a lot of work because there is individual opcodes for every sort of way to die.

it's called using a disassembler so i can't do that

can a moderator move my mod to the mod section plz