Semi is a very evil CTF level thoose blocks at the bases are so annoying ;P

But there are alot of cool tricks you can do with the RF's in Semiconductor.

BBlair: this is a must level to get used to playing. It's fun although blue has an advantage over red having the powerups and a carrot.

Zaitox: another great level to also play almost perfect but there is one place thats easy to get stuck in!

Distopia: Really good dueling level and 2vs2's and even at it's somewhat small size is ok for 3vs3's.