The game is actually still pretty fun. Although it reuses the same backgrounds and assets, each world feels surprisingly distinct from one another with the different level gimmicks and enemies you encounter. I’m not sure whether or not being able to go back was a technological issue or intentional, but it actually does add more to the challenge of the game in only being able to platform your way up instead of being able to readjust your position from far back. Despite being an old ass game, it also never feels punishing or unfair with most of the obstacles scaling really well to the progress being made with a really forgiving difficulty curve. Even though it's already a must-play just for its historical value alone, there’s also a lot to have fun with being a mostly solid video game that I could totally see being well-regarded if it just came out today.