I finished Doom I & II on an A1200 Blizzard1230/50 w. 32 fast, I got 12 to 15 fps, which made it quite playable, I used Doom Attack.
You can play Breathless and Nemac IV on the same setup, but if you want full screen you really need a 060. And if you play Quake, then you need a 060 to play it.
The blitter was good at handling vectors and filling them, that is why so many flight sims ran good on a stock a500.
By the way, Cro-Team who made Epic for the amiga went on to create Serious Sam on the PC IMHO on of the funniest shooters ever made. I wish we had that game for the amiga.