How do I control Hellmouth?

After some trial and error, the keys I've been able to find are:

Player 1

  • Movement: Cursor Keys
  • Attack: B
  • Jump: N
  • Grab/Release: M

Player 2

  • Movement: WASD
  • Attack: R
  • Jump: T
  • Grab/Release: Y

I'm not sure if there are more that I'm just missing.