I absolutely love BT1 and 2. My only complaint is the game is WAY TOO EASY. By time you fully upgrade (I went heavy tank) up can just keep moving to the next bubble without stopping or aiming.
Is a good start. Feels like the towers has to built in a certain order inorder to get anywhere. I got to the point where I had 4 auto cannons, 4 heavy, 4 missle launcher and 2 laser and was overran. The upgrades did not seem worth it for the price paid.
Game stopped at the end of wave 20 with no idea if it was finished or not. Completed the game on medium using only 20 advanced and 20 ground cannons. Liked the unique spawning style mobs however, this TD is extremely unsatisfying.