×Kill the Roach queen on the first move (Enter facing North-east). Rotate to face east and wait until the goblin stops moving. The goblin should now be North east of you. Using rotation moves and stepping, try to see if you can get him to go into the room's entrance from 2N 1E. Once he's in that area, you may need to wait for a move to let him get closer to you, and then you should be able to rotate towards him and corner him, killing him by stepping.

×Try using the trapdoors to your advantage. Try to get the goblin trapped in an artificially made corner along the edge, or somewhere in the middle, where you can use the crumbly walls. Remember to use your sword orientation to keep the goblin at bay.