I love clicker games! I did a strategy where I only bought the coin upgrade. Soon enough I was making 2000 coins per hit and then I bought all the summons I could, big mistake, my ears bled from the sounds of 50 or so ninjas slashing away at the chest, but it was worth it! I would make it so that the price of the upgrades increases a little bit with each purchase (dont tell anyone but, I love that the price doesn't increase in your game). The ending was great :D. Solid art, animations were smooth, I would maybe add a bit more feedback to the player when they buy an upgrade or when they hit the chest, but other than that, pretty great!