If you have Steam, I highly recommend playing this demo because it's super fun. And it's free, so why not!?
It's a top-down twinstick looter shooter with procedural generation and an endlessly scaling difficulty. Think Dead Ops Arcade with the PVZ artstyle.
The demo does not have progression, upgrades, or unlockable characters, but the full release will, and the core gameplay loop built around it is fun on its own that I doubt grinding will feel like a chore.
It really does feel like it's from the old school mobile era back when they actually tried to make good games.