Bad bug and non-intuitive gameplay
First off, theres a bug where King of the Sky and the giant worm upgrades are swapped. Seems known (and obvious) so a fix is expected.
Second, this game doesnt really feel good to play. Even if you react to enemy attacks and dig, you often get hit on your tail. Later when there are bunches of enemies with projectiles, you can lose a lot of health this way. On top of that, the enemy speed adapts to yours with way too high a maximum. Its almost pointless to get speed-up tokens because the enemies will often just match your pace and get subsequent attacks. The enemies are only fun to fight when you have a transformation that makes you invincible. (Which makes the previously mentioned transformation bug even more frustrating; the giant worm is slow so it doesnt help your progress like the others.) I do think the core of digging and jumping feels nice, but the camera can even stymie that as you can be blindsided by lava traps that were off-screen moments ago.
All-in-all it provides a decent distraction due to the carrot of the upgrade system, but is not fun to actually play.
Escarghoti about
Dragon Hills, v1.2.0