shapeshifter is fun on my A1200/030/50, and yours beats it by a few mips
I run photoshop on mine, and play marathon etc. Not having an MMU for screen refresh might slow it down a little bit.
There are quite a few nice emulators in general for AGA: Gameboy, Speccy ,C64 (magic64), MSX, PC to name just a few.
Game wise, you could test it out with TFX, gloom (2 player is good on a 030/50), genetic species, doom, I think there's a decent port of SCUMM engine doing the rounds as well. eye of the beholder 1 & 2 have both been ported to AGA.
Eagle player is good for MOD tunes etc. Also, if you like MOD tunes, try out tracker Hero (guitar hero for MOD's).
And of course plenty of demo's, but not the most recent ones
you'll probably have more luck with stuff from the nineties.
