I got upgrades to work, but I found what might be a bug. One upgrade touts that ships will start dropping gems at the cost of losing the health packs that spawn. Ships were already droping gems and I never saw any health packs at all. (I did get goo drops from ships and astroids, just not any pods.)
Gaining damage is fun; but I don't know what my ships base damage is so a number like +2 is too vauge in its actual value.
I'm not sure what you're looking for in terms of feedback. (If you would like you're players to look out for certain things I'm sure they would if you announced it.)