Keep in mind that this is a toy built to resemble something Bay's team had created. It isn't just a case of 'turn a microscope into a bug creature, and be free to make it look weird if you want'. Think FAB Frenzy - it wasn't the best looking toy and was very fiddley, but that's what we ended up with for Hasbro to create a toy replicating that movie character and its alt-mode.
Scalpel's bug mode does a good job resembling the movie character (from pics seen so far), and we just have to wait to see what the alt mode actually looks like in the movie as well.