Fun core gameplay loop, love a good trajectory game. Also, it didn't have to be in 3D but I really appreciate that it was, added some cool depth especially as the camera pans around.
Some minor feedback, I understand that it makes sense for the axe to be planted once it hits something, but maybe a bounce when hitting an enemy would be cool to chain those standing in a row. And while the core gameplay is fun and addictive, some variety in enemies or added risk and upgrades for the axe could make it more dynamic and fun for longer. Great work!