I think SDL would be ideal for writing an old 8-bit style game. In fact I used it for exactly that a while back porting a game I wrote in 1991 to run on Windows and Linux. If you were brought up in the 8-bit era then SDL brings back some of the visceral thrill of poking things to the screen and fiddling with the colour map!

I haven't tried SDL in perl (only in C) but I note there is what looks like a comprehensive set of bindings here - SDL. Don't be put off by the huge number of things you can do - like any good API it is very wide and shallow. Just make a screen and get poking!

SDL itself runs fine on many platforms as I'm sure you know and I ported several SDL programs to windows and linux. I'd imagine if you could get the SDL module to compile on a given platform then your game would run.

I'm sure perl will be fast enough - after all we used to write this sort of game in BASIC with a smattering of assembler to plot things and you've got SDL to do that.