I had a look around, I remember playing the game years back, I think you could make him a little more like the creature from the game with a few adjustments, it's easy to do realistic/wildly different versions of a character like Mario or Mickey Mouse because (a) they're so well known iconic characters and (b) they have a lot of recognisable accessories - IE hat/gloves/yellow pants etc.
Because you've departed so much facially , you may as well have not mentioned he's the horned reaper, as right now, aside from the horns maybe, there's little to compare.
There was a guy who made a high-poly render in SoftImage which got quite close, and was still recognisable, even without the giant toothy grin.
Here's a rough paintover, if you pulled out, stretched the chin, gave him a stronger jawline, a brow ridge, pronounced cheek bones and adjusted the horns so they appeared to grow straight out of the skull ( rather than what appears to be curling around first, then going straight ) then you'll be onto a winner.
Note how the softimage version and the cartoon version still captured the essense of the character without departing from it so much you couldn't recognise it.