Nice job! It plays well.
I felt a little cheated out of my coins when I didn't have enough time to pick them up before the shopkeeper appeared or they de-spawned(?). Maybe not having them de-spawn or having a auto collect when the shopkeeper appears would be nice. I would have loved to be able to purchase multiple buffs from the shopkeeper as well.
In the last area enemies get caught very easily behind the trees making it a balance of trying to kite the enemy around the trees enough to kill them before they get to you. If you have time some pathfinding to get them to go around the trees would be appreciated.
Really great start!