For a first game, this is pretty good! The art is nice and the core gameplay system works reliably, which is always the fundamental point of a game. As others have said, potentially fleshing out the upgrades system, with cool animations/SFX/minigames/other unexpected mechanics would make it a bit more engaging. My other feedback would be to make it a little bit clearer what the upgrades do - perhaps with a hover label.
Good work nonetheless!!