Western Friendly!
First of all, let me say that if you are on the fence about this title, you can pick up a demo on the japanese store, there is also Spelunker World on PS4 but the Switch version is far superior if just for the framerate bump alone (PS4 @ 30fps / NS @ 60fps).
The game is essentially a skill-based action puzzle game. You'll run into obstacles that can easily kill you so it is up to the player to be a quick thinker to prevent imminent death, and of course as you progress, the game will throw multiple obstacles at you at once as well as giving us new ones to deal with.
Bundled with that are level-ups, gear that can also be leveled up for different effects. somewhat of a "dress your avatar" concept but where the game shines is through the "buddy" system when playing multiplayer, online or local up to 4. Matter of fact, the game strongly encourages playing with people as some mechanics will only be achievable in doing so, but again, the game to it's very core was designed for the main language to pretty much be explained through images, so a total noob like me that that has extremely basic knowledge of hiragana or katakana (yes, no) will easily get around the game with no problems, just don't be scared to push the buttons to find out what they do! :)
If I was to be more specific, I'd give this game a 4.2⭐ for: cuteness, fun, replayability, challenge and functionality, this game really feels like there is no glitch and the online does not feel too laggy.
I would recommend it in a heart beat, at least to anyone that can enjoy a good old challenge!