A nice take on the theme! Memorising the different mushrooms was a fun challenge.
It could do with a more balanced difficulty curve. Maybe introduce the mushroom species gradually, and slow down the spawn rate. I ended up with mushroom clusters so dense that I had no idea which one I'd be eating.
It would be good to show the final score on the endgame screen.
The art is pretty, if a little stylistically inconsistent. The music felt appropriately "caveman-ish".