Osu! is a rhythm game for PC and Mac (with a new open source client in development that will also support Android and iOS). Essentially, you play to music. People arrange 'beatmaps' that have specific timings to specific songs. Osu! has four game modes, one based on Elite Beat Agents (or technically its original Japanese version), one based on Taiko no Tatsujin, one based on basically any generic rhythm game that plays similar to a piano, and an original one where you catch falling fruit. It's free to play and I recommend you try it. https://osu.ppy.sh/
Actually I've since made a newer design pretty recently that's a bit more original, probably more optimised for 3DS, and closer to Laser in looks. Sono asked me to do it, but he didn't say he was working with someone else, so I thought you both just happened to work on the same thing by accident.
Also, he hasn't mentioned it at all since then, so I thought the project was already dead.