What a fun little-known game I have found. Iwate Mountain Dance would actually slip through my radar these days, with all the compromises I've had to make to at least somewhat cope with the insane amount of games being released daily. Which is sad, because I think this game deserves a bit more recognition. Just a bit though.
Iwate Mountain Dance is an action platformer bullet hell boss rush. That jumble of phrases actually delivers a very complete overview of everything the game offers. There's no levels, no upgrades, just a bunch of bosses, each with a unique gameplay mechanic, unique bullet patterns, and you with a double jump, a mid-air any-direction dash, and 3 lives to take each boss down.
Each boss has several stages, with a slightly different twist on the main mechanic on each stage. Some bosses are more difficult, some have more stages, and I think some are optional. However, the game's so short (a few hours, depending on how good you are), you'd be doing yourself a disservice if you didn't beat all the bosses despite liking the game.
I have not played any official Touhou games, but this very much gave off Touhou vibes. (I checked, and the developer's only other game on Steam is a Touhou fangame, so I guess I was right?) I'm not sure what makes it so. It's not just the bullet hell gameplay. Maybe it's the overall art and music theming? Maybe it's that a separate track has been made for each stage of each boss, which is a crazy amount of music.
In any case, I feel a lot of care has gone into this game, but sadly the execution could be better. The gameplay doesn't feel precise enough for a bullet hell. Probably because a keyboard only lets you move at max speed or no speed. They could have just made the character follow the mouse on the horizontal axis. The game's a bit too short to really get into it. And while I feel the art and music are thoughtfully made, they aren't of a particularly high quality.
I'd give the whole thing a partial recommendation. I think they did well to focus on just making boss fights and nothing else around it. As a result, the gameplay feels well-balanced, and there's no distracting elements that I might dislike. The fights are fun despite the sometimes frustrating controls. I just wish it was of a higher quality and longer length overall, then I could give it a real recommendation.