At least he let me know that making it Vista compatible stops him. I'm not sure if it stops all decompilers (or how many there are for that matter), but it's a start.
No more discussions about decompiling someone's code, OK? That's just wrong, even if your intentions are just for learning. Instead, just ask the author for samples of his code. If he agrees to give them, that's fine. If not, that's fine too.
But either way, DO NOT take what doesn't belong to you. That's a great way to get banned from the GMC.
I'm not sure how a surface would be faster. I guess you'd just be drawing one big sprite, though there aren't enough sprites here to REALLY slow down the game. If you're finding it a tad slow, then exit out of the windows I guess. They're sprites for the most part. I've found GM can handle... oh... About several thousand sprites before it really starts to slow down. I don't think about 4-5 per window (plus text box sprites and button sprites) would really slow it down too much. Remember, the bigger the particle gets, the slower it is! If anything, any slow down of the windows may be helpful. I mean, you're games aren't just particles, are they .