http://www.mediafire.com/download/um9xl ... GICHAX.gmk

I'll need to put out a V2 of this, there's a few things regarding alpha blending and some optimisations that I've since been able to do, but in short: this allows your 240x320 native game to make a duplicate render to a resizable rotatable surface, and then hide the actual window.
Unfortunately this isn't quite what n0rty had in mind considering the game's still running in the top-left corner (just hidden) meaning you're effectively running the display of the game twice, increasing performance requirements, rather than just picking your render and only rendering once. Why do I do it this way? GM sucks and Yoyogames and their forums aint gonna help.
Pros:
- TATE on the fly
- wallpaper backgrounds!
- alternate game layouts (Aero Flux, Trig Wars and GMOSSE layout all in one)
Cons:
- still need a game reboot if you want to change window size (a must for this)
- not everyone can use surfaces
- higher performance requirements