The game is out now:

I took it for a spin last night and played most of the first world.

On the whole, my impressions were very positive. It's vibrant and beautiful, the controls/physics feel good, the music is fabulous as per usual from David Wise, levels are well constructed, and while it wears its influences on its sleeve, its definitely more love letter than plagiarism.

My only issues are that the Switch version is in a bit of a rough state at the moment, with very long load times and some hitching. The good news is, I contacted the devs and they say a patch to fix this is already at Nintendo for approval; they were hoping it would be ready for launch, but Nintendo apparently take longer with this stuff than Sony/MS.

So while I would heartily recommend it to any fan of classic platformers, I'd say if you plan to buy it for Switch, hold back until the patch goes live.