Astral Chain can provide a pseudo co-op experience

Astral Chain will let you enjoy some co-op action during the action segments. While it's not a fully fleshed-out option, it does indeed let another player jump in on the fun. Astral Chain director Takahisa Taura explained in an interview with Kotaku.

“I thought as I was developing the game that, of course, it could be made into that kind of system where it could be split up, but generally what I wanted to do is have one player control two characters at the same time, but the Switch actually has this great feature where, obviously, you can detach the Joy-Con and share play. We wanted to take advantage of that as well.”

When you split the Joy-Cons, one can be used to control the cop character, and the other will control the Legion you're tethered to. Taura says playing this way is actually more challenging than going solo, but will provide fun as well.

“If you’re going for a high score, it’s challenging to do this, playing in two-player. As one example, while you’re playing the game, there are several synchronous moments where you’re doing attacks with the Legion at the same time. And if you’re playing two-player, the other player and you—actually, it’s almost like you would actually have to be of the same mind. ...but it’s not just that it’s hard. If you’re sitting next to somebody and playing this game, it’s also really fun.”