"Oh snap! Another unique map!"
The Wall is the second unique map encountered in Trimps, found in maps of level 15 or higher. Completion of this map rewards Bounty.
The player needs a minimum of over 1.76M combined health and block to guarantee completion. That number is the minimum attack of the worst possible scenario on this map - a Snimp encountered on cell 99.
The player should aim for combined health and block of somewhere between that and the maximum attack of that imp (2.64M).
The cell 100 boss - Brickimp, doesn't attack first, therefore its attack doesn't matter, as killing it is only a matter of time.