And that's what MegaMan is ultimately about: Play a level, beat the boss, and earn his weapon. Use that weapon against the one boss particularly vulnerable to it, get his, and repeat.
This unfriendly mechanic is backed up by some incredibly polished platforming action. MegaMan doesn't do much, but everything done is done exceedingly well. Controls are tight and responsive, there's no momentum or slippery floors and you can only shoot left or right. Even weapon selection is designed to minimize frustration: press start, pause the game, and select your weapon, resuming play only when you're good and ready.
MegaMan knows its strengths, and the whole series never strayed far from them. If the core platforming action is your bag, then the whole game will likely tickle your fancy from stem to stern. I very much love that it doesn't fuck around with extraneous crap, there's no collecting or score or timers.
It's just so damned simple and that appeals to me. There are a few frustrations: some of the last bosses were very random, and the game punishes you hard in the last stages with some inexcusably difficult vertical climbs with enemies on the walls, and since MegaMan can't shoot up they're balls hard to kill while saving your health bar for the imminent boss.
I would never have played this game to completion back in the old days, but with emulators and save states, used as sparingly as possible, I enjoyed the shit out of MegaMan. And I love the graphics and style, it's serious about being cute and approachable.
And that's MegaMan X in a nutshell: it knows what it wants to be and it doesn't get all insecure about it by overwhelming you with anything at all you don't need.