Thank you for the shortcut showing.
Actually, the D4 water was put to lure the player. Unfortunately,
it was the source of the shortcut. Now, I put Red Tunnel to
replace the water at D4.
The complete changes are:
Red Tunnel at D4 (to replace water),
Ice at E1 (to replace rightward tank mover),
Ice at E3 (to replace leftward tank mover).
I'll submit the changed level to Donald when he is back home.
Bye,
Suyono