Thank you for playing and posting feedback. Time run out, so i focused on get it playable. I will add all the upgrades in the next versions. The Waves are really too long in the first 20 waves. i wanted to introduce each unity for themself. like you said, they have different attacks, armor, speed and so on. With wave 21 the real game starts. In one of the next upgrade i hope to integrate that the player can choose the time between the waves and when click on the wave-timer the next wave starts.