Glad you finally got it! Looking forward to hearing your thoughts.
Visuals and Audio:
The visuals and audio are charming and fit the game well, but they are nothing to write home about. Nothing stands out about it when I think about the game so they were neither offensive nor impressive.
Controls:
In a game like this they have to be perfect, and they are. They are simple (there are only three actions in the game: jump, grab and dash) and responsive, and surprisingly the Pro controller's atrocious dpad is not an issue as up/down doesn't do anything.
Gameplay:
Ah, it's a brilliant mix of puzzle platforming and exploration for hidden rooms and collectables. The three actions all combine into a really satisfying gameplay loop and each room is a puzzle to solve with your limited grip time on walls and your dash which only replenishes when you touch solid ground. The collectibles also only register when you touch solid ground so don't use suicide runs to try your luck at grabbing them.
Difficulty:
This is the most surprising aspect, as I remember reviews saying the game was hard, but despite having died over 300 times so far (I think I'm half way through) I was never frustrated. If you ignore the collectibles it's an easy game, but finding and collecting them means that you will die lots. The game never feels difficult (frustrating?) though because you respawn instantly in the same room right by the platform or collectible that you were trying to reach. Some of the collectibles so far have really had me thinking hard about how to get to them.
Edit: I take it all back, B Sides is delightfully difficult!
Summary:
I think the quote "It's OK to fail" sums this up well. I have never played a game where I've died so many times and never once felt frustrated, and I can highly recommend this to people interested in puzzle platformers. If this game had a rocking chiptune soundtrack and funky pixel art then it would have been as if it was perfectly tailored to my tastes, but the relaxing ambience does add a certain charm to the proceedings.