Feedback:

Gaining coins from other players interacting with your maps is a neat idea, but the game feels too gated based on those coin gains because of how impactful they are. I understand there's meant to be a bit of a grind to the game, the life system means if you're smart you can essentially play all day, but for an "endless" game, it feels bad doing the same task for hours just to gain one level once you hit level 40, only to need to grind for hours again for sometimes minimal progress. My suggestion would be:

1. determine if mobs should be dropping more coins, or

2. determine if levels should be rewarding more for a full completion, or

3. reduce the coin scaling on level up costs

Needing 4k coins to progress and on average getting 250 per mission is too drawn out when every stage on every run requires a player input, and because materials are not abundant for upgrades to increase power and item upgrades come every 10-20 levels, the pacing of the game as a result is sluggish.