Thank's for your input! I'll be patching the game with a bunch more upgrades soon. They only show up after you die and have enough gems. So that might be why you aren't seeing it. (There isn't a button for it.)
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.)
EDIT: Found the issue: https://imgur.com/a/YCq4XMO
I was just playing it the other day and noticed that (like you said) the gem carriers are getting spawned without the upgrade. Which I believe only started occurring after I fixed an animation bug, go figure.
Anyways -- as far as damage goes, internally the damage model is bare bones. Everything is stored as an integer, and damage applying functions floor or ceil the decimal in your favor. So if you're dealing damage, the value is rounded up, and rounded down if you're getting hit. Here are all the constants related to damage in the game:
PLAYER_HEALTH 100 RAIDER_HEALTH 45 BIG_ROCK_HEALTH 6 SMALL_ROCK_HEALTH 2 HEALTH_POD_HEALTH 20 BASE_PLAYER_DAMAGE 1 RAIDER_BULLET_DAMAGE 15 BIG_ROCK_DAMAGE 25 SMALL_ROCK_DAMAGE 5
Honestly I'm surprised the game isn't more buggy than it is. The the main source file -- where all the game code resides in -- is 2600 lines of C, built on a handmade engine, and it's a mess. While I'd love to have the time (and by extension, money) to continue to improve this small game, it's not really an option right now. If you are interested, I've made a DevLog about the state of the game.
Althought it is sad to see a project shelved, its nice to know of a silver lining. I hope this engine you're making begins to really shine one day. In the mean time, I'll be on the lookout for your various small projects.
Thank you for sharing your game!
P.S. I appreciate how open you were with the details! It's alwasy nice to have closure.