Well i got round to testing that as it was sat on my pi anyway i can confirm contra 4 works fine i have a us dump if its relavent and if i may suggest you could try checking your controller mappings see if shoot and hook isnt mapped to the same button by mistake you never know may have overlooked it but it is working fine infact ive just been playing it with my ps3 controller on my pi with enhanced resolution enabled(actually gives 2d games a nice crisp appearance instead of the default blurred one)