@Shadowsithe and ak_
I agree totally - I don't want to drastically change the gameplay as I'm sure it would have a detrimental effect. I consider this version a complete game anyway so the next version will either be 'Protozoa 2' or 'Protozoa enhanced' something along those lines, the point being it won't replace this version on the archives.
I must admit having thought about it more I'm not keen on the bouncing off the tail idea - there is nothing wrong with it as such I just think it would alter the gameplay too much and would be better as a concept for a separate game. Power ups I think would also upset the balance - however i will be including some form of bonus objects - probably just higher scoring organisms.
Basically although I will be adding lots of new things to the game I intend to keep the spirit of the game the same.