Great game! Really fun to play and keeps getting more and more difficult as promised. Graphics are simple but really effective and music and sound effects set the mood for the game really well. The idea that upgrades also have drawbacks was really interesting concept and also added some tactical aspects to the game. Although based on my (very limited) time playing the game I think some of the attributes are just better than others. For example upgrade on shoot speed made killing enemies a lot easier even though it decreased damage and the reason I lost at the end was that I accidentally allowed decreasing the bullet life time which led to a situation where killing the enemies was almost impossible. Would be also interesting to know how the numerical values for the tradeoffs are determined?