The traditional aircraft for game counting is a piston Cessna. Low and slow with good visibility for observers is the primary need so high wing is best. A Twotter would do the job but would be seriously more expensive to operate.
The C208 would be a bit on the expensive side but give me a PT6 rather than a piston engine any day.
The BN2 is just the wrong aircraft for hot&high operations. Where the single engine ceiling is underground the remaining engine just gets you to the crash site a tad sooner.