This feels like like quite a solid tower defense game! At first I thought the memes would only start attacking when I placed my first tower, but turned out they're just on a timer. Also, the book felt a bit too weak, but y'know, just might be a skill issue... Also I didn't really understood what the drums were doing? I think they slowed the enemies down? A small text explaining what everything does would be useful.
But all in all, nice idea!