Listen, I'll try to make this review shorter than this game's levels. The summary of the review is... cut the levels by half, and this could've been an infinitely better game.

As much as the upgrade systems were a little difficult to grasp (that's on me for not reading the manual...), I did enjoy the feeling of scaling my way up the vertical stages, and strategically taking down the enemies in my way. The dungeon-like levels and horizontal ones weren't too bad either.

My willingness to replay this game again however, is ruined by the exhausting length of each stage, its layout copy-pasted several times to pad things out. If they wanted Kid Icarus to feel like a grand adventure through how big it is, that's fine, but you're gonna have to do a lot more than this. As it stands, there's too much here for too little gain.

The only reason i started playing this game was because of a challenge with my friends. There are some really cool and innovative ideas in this game, but the execution is just pure and simple garbage. It doesn't feel good to criticize a game that is way older than me, programmed in the ancient times of the 80s, but there were so many better games at the time. It's not the limitations of the technology that made this game terrible, it's just bad choices.

The first three stages were kinda fun actually. There was some problems like slight delay in the controls that can result in some deaths (mainly in the slipy ice) but at least it was kinda funny. And then come the first boss stage (1-4). This is the moment when the monster that designed this game shows his true facet. The enemies have way too much health, and not only that, but there are enemies that can transform you extremely easily into a state where you can't fight. So, along with the fact that they have gigantic health, you can't defend yourself unless you perform a miracle and find a place to remove your curse without dying to the multiple enemies falling from the sky or throwing things at you in the way.

There are also multiple moments when there are so many monsters on the screen that not only does the game slow down, but you can't avoid the damage that comes from all directions. It's just annoying really hard game design that feels really bad and unlike Castlevania (which was released in the same year as this game), that feels fair most of the time, Kid Icarus is just a unfair and uninspired experience that try the best it can to stretch it's gameplay time by ruining what could have been a really amazing NES game. It's no surprise that this game never became a big franchise on Nintendo.

TL;DR: Not fun. Avoid. Play something else.

While I played the original Kid Icarus on the NES, most of my tenure was spent playing it on the Wii virtual console. Often maligned as Metroid's deformed cousin, Kid Icarus is hard. Especially the first world, which was often a common breaking point that people failed to get past. God knows I stubbornly grinded my face against it for hours until I got to 1-4 and the game opened up. Figuratively and literally, the 4th levels of each world are dungeons where the Metroid comparisons come into play. Also the power curve of Pit through the game bears some similarities with Metroid.

Truth be told? I like Kid Icarus more than the original Metroid. It's linear, sure, but the tightness of the controls makes it feel good to play and unlike Metroid you won't spend the entire game getting lost. They really aren't comparable though. I think as far as platformers go on the NES, you can do a lot worse than Kid Icarus. I'd even call it "good".