For those who haven't played a Hatsune Miku rhythm game before, this is a perfect one to start with. There is also Future Tone on the PS4, which is also a perfect Hatsune Miku rhythm game. You can't go wrong with either. These are great fun, but only if you're all right with the sound of Vocaloid music. (And Japanese vocals, which are sadly usually not translated in-game.)

As someone who has played all the Vita entries, as well as Future Tone on PS4, picking up Mega Mix on the Switch as well wasn't really necessary. But I feel like the game is a nice fit for portable gaming, and I'm also a big fan of the more "anime" cel-shaded look this entry went for. There are some new songs added to Mega Mix, but they were made available as DLC for Future Tone if you don't want to buy another game. I believe in the end Future Tone still has quite a few more songs than Mega Mix -- but regardless there's a ton available in the latter via its own DLC packs. (They've gone on sale pretty regularly, if you're patient.)

At any rate, I love Hatsune Miku, and her rhythm games are god-tier. Nothing too fancy, nothing too out-there. Just simple button timing, but the "level design" for the rhythm patterns is top-notch for every song and for every difficulty level. I've also always loved the variety in music these games have always had. Slower and sad tunes, upbeat and bouncy pop, full-blown rock, faster and insane songs... There's something for every mood.