Even after 25 years this game is still fun to play. In a sense it’s the granddaddy of platformers (though by far not the first, it’s the one most remember when speaking about their first platformer game), its entire design is a hallmark for greatness. All the platforming elements that seem so generic these days (jump on things to kill them, get power ups, moving platforms), the controls that feel slightly lacking (rage-inducing momentum) when compared to for example the SNES Super Mario World with its much more precise controls, felt revolutionary then. I still remember seeing an arcade version of the game with a cluster of kids standing around trying to beat it.
Sure, all things considered, the game looks its age, but that doesn’t change that it’s a game that can still be enjoyed today, not just as a historical artifact, but as a game by itself. You don’t have to fight an inane control scheme to understand how to play the game, even gamers who’ve never played this probably get it in a few seconds (though with the new generations of players growing up with touch and motion controls this might change).
But while the game follow a philosophy of simplicity, each new world manages to introduce new gameplay elements you have to master, new enemies to get around, new deadly traps to avoid, more tricky jumps to do. You’ll learn as you advance, in a progression that feels entirely natural. From the easy peasy initial levels to the more challenging levels later on, you’ll never feel like it becomes too hard, as you’ll go with the flow and master the game while playing. It sounds simple, but it’s one of the hardest things to do in games, remain challenging without becoming frustrating. The hallmark of any truly great game.