This game was very well produced and balanced. I could feel the difficulty ramping up while still enjoying the power that came with each upgrade. Even with explosions and metal music ramping up, the audio and visuals were still clear and readable. Everything was responsive and worked well.
In implementing the theme, the game took away one of my favorite parts of the 'Survivors' formula: Choice. Without any options, I was unable to strategize my build in the slightest. I at one point received 7 bullet size upgrades in a row. Another time I was healed when already at full health. I'm not sure where else you could go with the theme here, but taking away player expression is not my idea of good theme usage.
Game also went unresponsive when I selected to quit -- I'm assuming because that button was meant for a different platform haha.
Good game overall, I just spent a lot of time above explaining my one complaint.