At first, as people stated, the game gets boring quick because the starting waves are easy but way too long and empty. However, I encourage these people to keep playing the game and make it past wave 8, as the difficulty starts scalating quickly, making the game challenging and fun!
Being able to move your camera by using the mouse would have been interesting, but since there was a useful minimap showing everything I needed to know, I hadn't any problems with the lack of this feature. Also, the game's beat is fire, I really loved it!
Nice work!