Pros

• Good selection of playable characters. Though I haven't tried them all (why would anyone willingly play as Caster Gilles), the ones I did play have fun combos and special moves that keep them feeling different enough for me.
• WADARCO character art is always welcome
• Music is pretty good; it's got a new EMIYA remix so that alone helps quite a bit.
• Because this game is on Switch, there is a non-zero chance that Saber could be added to Smash Bros.

Cons

• Levels can get repetitive
• Not terribly difficult; I don't have much experience with musou style action games
• Story was not terribly exciting standalone; you could probably read a summary online and not miss much. That's a shame because the first game (Fate/Extella) was reportedly much deeper, and also much worse gameplay-wise.
• Things won't make too much sense if you aren't already somewhat familiar with Fate lore. The hell's a Servant? What's with the program-based command codes? Moon Cell? What???
• I didn't care much for Nero

All in all, an okay game for existing Fate fans but not something I would recommend in general.