DraStic

the problem is this: it was flawless all the way until I was fighting the big bad (team galactic) and had no healing items on me, so I savestated and input a couple of cheats.

cheat 1: Max Health (said to press start, didn't work)
cheat 2: Inifinite Health (it worked)

both cheats were highlighted when I beat the big bad, and then it went to the cutscene, but instead of showing a bunch of ruins and people with anime hair, it shows a black screen with purple blocks one in each corner, and a block on the bottom portion of the screen.

I still get a dialogue box, but nothing else.

PLEASE HELP! I spent 8 dollars on you guys, this shouldn't happen (no offense intended if that came across rude)

Make an in-game save, disable the cheats, and restart loading from the in-game save (do not load from a savestate). Maybe the cheat breaks things, it's possible it's an emulator bug or it's possible it's a cheat bug. We can't really test every possible cheat in every possible combination.

its only a big issue as you used cheats. that makes games go into aneurysms at times and circumstances.

Rule number 1 when using cheats. NEVER use savestates...