All right, so, Yoku's Island Express (which is currently on an 80%-off sale on Steam, for $3.99 USD, until June 27) can probably be best described as "Metroidvania pinball." Steam says I played it for 10.7 hours, and the game save considers itself to be 100% complete (even though I didn't get all of the Steam achievements for the game, and since some of them are dumb busywork stuff like "toot the noisemaker 1000 times" or whatever, I probably won't bother).
You're playing as Yoku, a dung beetle, who arrives on an island at the start of the game to begin his (or maybe her, as I don't recall the game ever really specifying if Yoku is male or female) job as the new postmaster. Ostensibly, your job is to deliver mail and such, which you do over the course of the game, but ultimately your job is to save the island from destruction, as becomes clear pretty early on.
So yeah, it's Metroidvania in that you're traversing a big open world area (with a few different "biomes" like "the desert area" and "the snowy area" and "the watery area" and such), finding new gear that lets you get to places you couldn't otherwise get too, and all that stuff. The Metroidvania part of the game is great.
And it's pinball in that you're very frequently encountering areas that are... well... basically just big pinball machines. The pinball part is... okay, I guess. It can be rather frustrating at times, especially those times when you know what you need to do to progress, but it's just a matter of getting Yoku and his/her little ball to cooperate. That said, even I managed to 100% the game (according to the save file, not Steam's achievement acquisition), and I'm not even really into pinball all that much. For the most part, I liked it well enough that I didn't ever rage-quit (though I did "this is exhausting, I'm done for now"-quit a few times). Basically, if you hate pinball, maybe avoid this game, but if you like pinball or, at least, are indifferent to it, then I would recommend this game.
Also... this might be one of those "better played with a controller, rather than keyboard" kind of games. Though, again, I managed to 100% it using keyboard, so... *shrug* (For what it's worth, it's also on consoles, like the Switch, PS4, etc.)
One hint/tip: when in doubt, try to find an explosive slug (it'll make sense eventually) and use it to launch yourself to a place that otherwise may look utterly inaccessible. The source of explosive slugs sometimes may be much farther away from the goal than other times, though. And it may take (more than) a few tries to properly line up the slug-side of your little ball to get the launch angle correct.