Hmmm, if i remember correctly, Genetic species has a patch that you can download to allow you to run in higher bit planes. If you want, i can email you the patch if its not available on the marble eyes website.
I dont think it runs any better with a voodoo than an aga chip, although it is pretty spritely if you use an 060. I'm not techy minded so i cant tell you why this is.
As for Bubble heroes, try reinstalling it, i have had no problems with using the RTG version in the mode i mentioned before.
Bye.