Really fun concept! I like the risk/reward factor of the game. And how nice of the dragon to heal us sometimes too :)
Clever title and charming art style. I like the characters and shopkeeper designs. I wish there were some sounds to go along with the game!
At first I didn't realize the green fireballs were healing & yellow were coins. I went in blind without reading anything. I think if they were a little more obviously coins (coin flipping animation) & healing (health + signs or hearts? maybe particles trailing it?) to distinguish it from the red damage fireballs, then it would be extremely clear and need no instructions. Once I got that concept, the game became really interesting!
Although the health projectiles did make it easy at times, it also made for some interesting pathing through the threats. I could tank some fireballs to get a bunch of coins if I knew there were health in the way too that would keep me alive. Again, sounds were desired here to give some feedback as a player.
I enjoyed the upgrade shop. The speed and magic upgrades felt nice and noticeable. I didn't really have much need for the health. Even when I'd enter the dungeon with 5/50 HP, I could just bank on the healing spells getting me healed up before I risk gathering any gold. After a few rounds, I stopped playing since it didn't feel like there was much changing in the levels, and it was getting a bit easy at that point.
But I had a great time playing and getting my squad nice and upgraded! Nice job on the concept and art direction.