I've been enjoying my time with the Sonic Frontiers' Final Horizon update, myself. It's really fun to play as the other characters after nearly two decades of not playing as them, and I think the new challenges the game presents are really fun!
Though, be warned, this update is hard, and I mean HAAARRD. I've seen people call it a "Kaizo" styled update, but really, I think Kaizo hacks tend to be incredibly cheap in their design that I don't think it's accurate. I'd say it's as hard as a Celeste game, nothing wrong with a bit of challenge, like I said, I've been enjoying my time with it, I didn't even mind the two Only Up-styled tower climbs and the trials at the top of them, but it WILL test your skill.
I say the hardest part is the Cyberspace stages, because oh my god, my blood was boiling way more in them than ANYTHING ELSE in the update. I haven't even beaten a single one yet, and I don't think I'll be able to 100% them like I did with the OG ones. They are even harder than everything else the update offers.
But overall, it's still a fun time. It's not hard that I'd say it's unbeatable or impossible or not fun, and I'm still looking forward to doing more of it tomorrow (pray for me in the Cyberspace levels)