Neath

Keyboard controls:
Z/C: jump
X/V: action
down: crouch
down + Z/C: drop through platform

Abilities:
Once gained, elemental abilities can be used by pressing the action button. Metal (white) allows a dash, which can break blocks. Water (blue) allows a geyser, the water from which can revitalize withered vines. Fire (orange) allows flame, which can be used to burn vines and jump slightly higher than normal (during a jump, press the action button).

Many thanks to thisismypassport for Shrinko8, without which this wouldn't have been possible.