This is one of those many games that I have seen unplayed in too many people's games list. I decided to give it ago to farm some trading cards after this has been in my library for a year or longer. It is in Early Acc..wait what? A game released years ago is in Early Access? Yeah, it is. I didn't quite believe it until I saw the stamp on the store page and the multiple reviews and discussion threads referencing. Many players feel the developers are abusing the Early Access status as an excuse for the game "being worked on" and not up to people's quality standards. Yet, Steam users report that the game hasn't been updated in over a year, so the developer is definitely doing some thing shady. While I don't care enough about this game to feel like I was scammed, I would probably advise most people to not buy this game despite the game in my experience feeling solid and semi-enjoyable enough to be played and possibly beaten. I don't honestly think the game is bad, but the player/customer experience is heavily damaged by the developer's strange behavior.
Another strange factor is that apparently this game has been redone multiple times. The game I remember seeing from videos years ago (even from a 4 year old video on the Developer's own Youtube channel!) is vastly different from what the game is now. I have no idea if it is better or worse, but it's strange to see a game have a completely different art style and game mechanics from it's release.
For the most part, gameplay is like an endless runner or a rhythm game played in first person as if you are sky diving around large shapes. Levels have different requirments such as getting enough points by getting close to objects, collecting items, hacking flashing objects by pressing a button while near the object or flying through a open object as if threading a needle. It's a rather simplistic game, but I think it generally works well for what it does, just it doesn't do too much. Some levels are based on specific tracks and other allow you to choose from a list a songs - you should be able to load your own music as well, but I've read at one person mentioning issues with loading custom music.
I think this game is rather alright, though probably a bad purchase due to developer scumbaggery. Fans of the other Dejoban games often recommend the other AAAaaaAA! falling score attacks games versus this one, so I would look into those first if this game piques your interest.