Stage 1 is a drag, you only get basically 2 upgrades.
stage one, the prices suddenly go from 10 to 1000, though the efficiency barely increased x2
Stage 3 you can't even afford if you debug some money.
it's a prototype with a cat emoji going back and forth. It didn't feel too rough, but some bullets fall off half way, which seem to still trigger the wall, but it's mildly frustrating.
It's not bad, but it's not a game, just a proof of concept.