Gee thanks! I've been updating the game since the first jam release, and I will implement your suggestions.
It's true that there are no core loops yet, I planned some upgrades and buffs with a normal currency and buy some skins and extras with special currency, but unfortunately it didn't make it tho haha. The only engaging part is killing some enemies, I'll add something to make the player play even more. I'll also add some reason to make the player mine the minerals, like get ammos and more coins (normal currency). There are more contents on their way as well!
by the way, some minerals have it's own score value, the rare it is the more you get!
Thanks again, I really appreciate your complements and suggestions!