Fun little game combining bullet heaven games with some incremental mechanics (and cute kitties).
Making moving a limited resource (which is also later used for healing) was an interesting mechanic that changes how you play. Though even the little ability that you do have to move is honestly a bit OP. I could beat bosses a little earlier than I probably should've with careful positioning.
The idle mechanic seemed tacked on to check a box and it was at odds with the rest of the game. It made it so half my upgrades came from just sitting around instead of starting a new run. It kind of discouraged me from playing the actual game as much as I otherwise would, because I was always just a little bit away from another upgrade so I might as well wait. I also avoided getting the upgrades that spawned more special enemies because I could just use the factory to produce more than they drop without the risk. In the full game I'd yeet the factory mechanic entirely.
The balance of everything is way off. A lot of upgrades straight up double the damage of the weapon (and those upgrades are somehow also cheaper than the other, less powerful ones). This means you'll just pump up the damage of one or two guns and ignore the rest. Some guns seemed significantly weaker than others, even with equal upgrades. A lot of the weak weapons also used more rare currencies that had more useful upgrades, which made them lag behind even more. The upgrade that lets you see the damage of each weapon just made me further upgrade the most powerful ones, instead of boosting the ones lagging behind (like i think the dev intended it for).
Upgrades that differentiate the weapons is a good idea, and I think you could push it farther. Do something like make the sniper target different enemies than the other weapons, etc. Extra damage to certain enemy types is nice, though not as useful unless it specifically targets those enemies. Also those upgrades tended to cost a lot more and do a lot less than just boosting the powerhouse weapons and getting more raw damage.
Having some upgrades the make the enemies harder is always interesting, though I tended to avoid them in favor of upgrading everything else and beating more levels. Considering you can't move and you auto-target things, adding more enemies seemed like a bad idea for how little of a payoff you get from them. I only touched them after I beat all the levels and figured I might as well use them to bump up the difficulty as much as I could.
The boss' shield 1-shots you, which is a problem in a game with limited movement and auto-attacking. A bunch of enemies spawn around you, preventing you from targeting the boss, and then you instantly die when you can actually attack. After you get the poison orb / tesla tower, boss fights turned into "hide in a corner until that kills them" more than actually fighting them.
"Can be completed in under 4 hours" is a technically correct way of saying the game is 30 minutes long. The game also gave the impression it was 30 levels long, but was actually 5 (and you only find out after it suddenly cuts you off). That left things off on a sour note of an otherwise good experience. Note to devs: Don't set an expectation at the start that you don't actually deliver.
It's a good game, but it needs some polish / balancing. I look forward to the full release.