Hi Helbo, welcome to the Wonderland forum!
The last room has chompers that come out of the walls when Stinky and Loof enter the room. There are nine bonus coins in each side in the fake walls (total of 18). If I remember right, I hid either Stinky or Loof in the wall after the chompers came out, then had the remaining guy picking up coins, staying out of the way of the chompers and exiting. Then the hidden guy can come out grab whatever coins are left and exit. It takes some patience and timing.
Good Luck!
