I kind of like this poster. It manages to transmit that “good old times” feeling, it’s splashy, and it introduces the main players and the story succinctly. It makes the film look as exciting as you could possibly make a documentary about two guy fighting for the top score in Donkey Kong look.
I do wonder why they don’t use any visual elements from the actual game in it. Due to rights complications perhaps? I imagine that is one thing that could have made the poster more attractive, at least to those of us old enough to be nostalgic for the classic Donkey Kong.