Bro, this was super cool! I like the idea of my money defending me from debt, it's too funny.
Content wise, I'm was a little confused why some enemies and coins had different varying speeds, even though they were the same entity. That added a little too much randomness that couldn't be overcome.
After a certain point, my coins were just too powerful that not matter what you sent at me, my coins could handle it. If there were alternate paths for the enemies, there would be a lot more room for strategy if you are also able to designate where the coins go back to once the wave is over. Just some ideas for if you continue to develop the game.