Despite being a big 2D platformer player, on the Switch I've only tried the Blaster Master Zero demo so far, specifically to get a handle on the control scheme. (Already have Shovel Knight on the Wii U, and not much else appeals so far.)
D-pad buttons on split Joy-Cons are... adequate, but I find that I have to hold the left Joy-Con quite low in order to give my thumb enough distance to travel comfortably, so this comes at the expense of easy access to L/ZL. (That is, I definitely wouldn't find it appealing to play VC ports of the 2D Metroid games like this.) In handheld this isn't so bad as you can grip the unit loosely, in such a way that the Joy-Cons don't fall against your palms. Even so, for long play sessions it's easy for this to fall into the same kind of scrunching that made it uncomfortable to play platformers for very long on the 3DS. The D-pad buttons are just too low.
This is why I keep saying that if they ever release a Joy-Con (L) with a traditional D-pad, the D-pad shouldn't replace the current D-pad buttons. It should replace the left stick. That would be ideal.
I enjoy the Switch pseudo-D-pad buttons quite a lot in Puyo Puyo Tetris, but the movements there are a lot more discrete than in a platformer, and buttons actually make more sense there than a D-pad would. The opposite is true for a 2D side-scroller where you need rapid movement.
That said, in the Wii U era, side-scrollers like Rayman Legends, DKCTF, and Yoshi's Woolly World moved towards design paradigms that were more about broad environmental interaction than the same kind of block-by-block precision of a 2D Mario game, making them at least bearable with an analogue stick. I expect first-party platformers like the new Kirby and Yoshi to follow this lead, but we'll need a better D-pad solution when 2D Mario, Mario Maker, or VC show up, even if it's just in the form of a Pro Controller manufacturing run that fixes the widely reported issues with erroneous D-pad input. And if we don't get anything of that sort, I guess I'm in the market for an 8bitdo.
So it's like Metroid in the way you fire your weapon, jump, and scroll the screen up/down/left/right. But not in the area of exploration... it's linear and there's definitely a path for you to follow.
I thoroughly disliked Cave Story when I played it on the 3DS, but sometimes I wonder how much of that had to do with the game itself, and how much of it was due to the extent to which everybody misled me to expect something that even remotely resembled Metroid. I might have to give it another chance on its own terms someday.
This happened with SteamWorld Dig and Shantae and the Pirate's Curse as well, and those were games I liked quite a bit. People kept comparing them to Metroid for some reason, and all that told me in the end was that an awful lot of players these days have no bloody idea what Metroid is and that you can't just slap that label on any side-scroller with a ranged attack.
