Yeah, I was able to get to level 50 with a ton of towers, but 50 is really freaking hard, way harder than DTD's level 50, which I always found really easy.

Actually, it appears that this isn't a sequel to the one we were discussing in this thread ("Desktop Tower Defense"), but some game called "Flash Element TD." It's certainly better made than DTD, but I hope there's a sequel to DTD soon, because it seems to me that it's author does a better job at balancing the gameplay elements. I also wish there were a cheat mode to FETD2 (sometimes I like to just take a break and utterly destroy those creeps ).