pixel perfick :
C2 has it's quirks, but on desktop platforms at least, it can generally hold it's own. I'm working on a bullet hell shooter now that can have 1000-2000 moving sprites on screen at times, checking cols against a few hundred enemies, all per tick(yes, cols too).
Plus particles effects, rotating enemies, multiple layer, parallax, etc.
I'm getting 60fps solid, with only occasional dips in debugger. Cpu usage maxes around 75, averages about 20-40, and that's also in the debugger, which adds a good bit of overhead, especially when you have a lot of moving objects. Now, I have a pretty fast processor (i5, 3570k), but I'm using it's integrated graphics.
TGeorgeMihai, lennaert :
I kind of reject the idea that Visual/WYSIWYG editors will never be able to compete favorably with hand coded games. Obviously, hand coded will always be faster (IF they are coded well...and that's a big if). But, in most cases, it's not going to be the massive difference that it was in the past.
If you doubt this, take a look at the original Construct Classic. It's easily as fast as many custom coded pc games...and in many cases faster. And keep in mind that it would probably be even faster by now had the Scirra Bro's kept on developing it.
Of course, you still have to understand the basic logic that goes into making things work, still have to refine your approach, but at this point in time, most of the lower level muckity-muck is best left to the computer itself.
I wish I had the skill, dedication, time, and talent to build my games from scratch, to work exactly how I want them to.
But...I'd rather actually make them...with C2.