Brushfire is the tenth level in Chip's Challenge 1. In this level, Chip must follow the correct path through the fire, and there is a bug in the maze of fire which will start to bother Chip after a couple wrong turns. In the 51 route, the bug is never seen.
The technique of window shopping is useful here - dead ends can be seen, and the exit becomes visible along with walls and fire suggesting that it should be approached from the south-west.
In the Lynx version, Chip receives a Decade Message, but not in MS. This lost message reads as follows: After warming up on the first levels of the challenge, Chip is raring to go! "This isn't so hard", he thinks.