I'm assuming it's a disk-based game... (ie, not installed on your hard drive.)
First off, is there a WHDLoad for that game? If so, most likely your problems are solved straight-up.
If not, boot your degrader and try turning off your DATA and INST CACHE. (Then pick the "SURVIVE RESETS" option and reboot and pop in the game's floppy)
If that doesn't work, repeat the same procedure, only this time turning off both the caches and choosing the "DISABLE FAST RAM" and again, survive resets.
This 2nd boot will make your Amiga nearly as compatible as a base unexpanded A1200. (And nearly as slow, as well. taking away that fast RAM from an 030 totally kills its speed.)