Scramble (arcade game remake)

[RokCoder]

Is QB64PE able to check how much graphics RAM is available? 

I've no idea - you'd need to check the source or ask someone familiar with it

How might we determine how much is needed?

You could calculate it or you could simply check for failure to allocate - I'm assuming the handle from _COPYSPRITE to mode 33 will be zero or similar if it's unable to copy to hardware. That's just an assumption though. 

A project for another day.

If I do anything else to Scramble, first it'll be editing in the hi-res landscape tiles. 
Also, before the rockets launch, they appear to be hovering above the ground, so that needs some tweaking. And higher res player bullets. And a Super Cobra mod? 
So many details, so little time!

Have fun!