Boo - doesn't work on Go Go Gelato. Dr Microbe looks great but seems a bit advanced for my son.
I don't know if the code works for Top That! but it is currently at $8 at Amazon:
I think this qualifies as a Hot Deal. Also the price appears to be dropping over the past month according to CCC:
I think it is a level below Dr Eureka. Kind of reminds me of Ghost Blitz with a little more.