Well considering the game had a 49 direction joystick, converting it to 8 directions just doesnt cut it for moving around too well.

But yes. Sinistar is indeed a hard game. Too hard in my opinion, and not masterable. (i.e. you can never get "good" at it to a point no matter how much you practice). That's why I think it's one of the weakest in the Williams classic catalog... although definitely one of the coolest vibed ones.