I’m not sure what the most original version was, but the one the screenshot is from is called Gorillas, and it was included with Mircosoft Qbasic, on DOS. It was intended as an example program, to show what QBasic could do. I modded the crap out of it, to make the explosions bigger and weird colors, etc. Changed the gorillas to be all mutated and fucked up, etc. Good times.