Rocks'n'Diamonds

PLAYER MOVES DOWN
R&D Engine: You die of standing next to a bug while standing in the exit. (The bug dies to sympathize with you.)
EM Engine: You live and win because you only had to "press" the exit. (Unfortunately, the bug lives.)

Well, it's not really a bug, but simply different behaviour in different engines. There are many such smaller and bigger differences in these two engines. Some of them could be removed by adding further options to R'n'D...

But it doesn't hurt reporting bigger differences like the one you mentioned above. :-)