It is the only way.

PLAY ON KEYBOARD

Asriel, you have lost your strength. You must regain it...

For Revenge.

It is the only way.

Essence is the key mechanic, try to keep on top of it as it is used up when you:

Double Jump (w twice)

Shoot (space)

Shockwave (E)

HELP:

Overworld - go through each door one at a time completing each level.

Level 1 - Make it to the end of the level.

Level 2 - Collect all of the screaming souls.

Level 3 - Place all the soul fires.

Try to find the hidden Kev!