A little rogue-like about a bag of money in a hostile dungeon

Coins are your life, your weapon and your currency

You can shoot coins at shopkeepers to buy upgrades (and you can stand next to them to see what they're selling and how much it'll cost you). You can shoot coins at reds to kill them (or you can try to avoid them). You can even shoot coins at walls to destroy them, but every coin you shoot is one less coin in your bag, so use them sparingly!

Reds move after every second step you take, and if you end up next to a red when it's about to move, you lose a coin. If you get hit and have no coins, you’re dead, game over!

Step on the staircase to go down to the next floor of the dungeon. As you go deeper, enemies get tougher and spawn in greater numbers, and shopkeeper prices go up.

How many gems can you buy before you die?