Thank you for playing our game and for the feedback!
Yeah as you said, some upgrades should make the game worse for the player. The idea was to make the player think the upgrades are for the better (by how they are described), but they actually come with a side effect. An example is just what you said about the explosion (but I guess it doesn't feel like it because the radius is too small).
The music is made by us, I guess we should've added the program that it was made in (it's Beepbox.co).