Nice job. I love the art style and the music was fun. It went pretty well with the sound effects from hitting the enemies.
Only critiques I have are that the hitboxes felt a bit off at times and it kind of just turned into a bit of a spam fest near the end. I get the later though. Have to get the game to end somehow.
I almost wonder if the game would be improved if there was a bit of a cool-down with the attacks. There was a bit of fun in being patient and waiting to hit the button right as they got close to me and it would be even better if the game actually rewarded me for that, rather than just spamming the buttons somehow. Would make that post-900 point portion literally impossible rather than figuratively so, but maybe that could be alleviated by lowering the cool-down as the lair got upgraded.
Anyways, here's a screenshot of my best score.