As a fan of Hyper Light Drifter I'm sad to say I was very underwhelmed with Solar Ash.
There are things I like still. Like the signature Heart Machine sound design, music and colour usage. The game has some cool concepts it's going for, like the unique "skating" movement and the Mario Galaxy-like gravity changes. And these foam-like surfaces you can skate on, that have some pretty neat physics going on.

My main issue with the game is that it seems like it wants to be this fast paced momentum based platformer with fluid combat and grapple hooks. Yet it's constantly halted by the need for the timestop mechanic, which freezes the game to a halt, letting you carefully aim your grapple hook or change direction mid air. It's not that timestop is a bad mechanic, but it has just a few seconds cooldown making the best play to constantly timestop in combat and during the obstacle courses. Like the timestop, there's also a mechanic of slowing, climbable goo that is found all over the game's stages. It's part of general exploring and in obstacle courses. This too slows you down to a crawling pace, which just feels awful in a game that feels like it wants to be a free flowing fast paced experience. It feels like this odd mix of gameplay styles that do not mesh well.
Sadly, the most enjoyable parts of the gameplay- the movement and exploration- doesn't feel fully developed. Often times the Mario-Galaxy esque gravity change and camera tilting does not feel smooth or even decided on what it wants as it constantly jitters back and forth on the foamy surfaces.
The momentum and inertia you would expect your character to have sometimes does not behave like you would intuitively expect. Instead you might suddenly lose speed mid air as you dash off a ledge, expecting to make it across a gap. Resulting in falling off as if you just walked off the ledge.

The game also suffers from annoying voice line hints as soon as you encounter a new mechanic or challenge. It's so on the nose and tastelessly implemented and feels like an insult to the players intelligence every time. It leaves no room for the player to experiment or enjoy the process of figuring things out. In the first boss encounter I had not seen the boss for more than a second or even approached the boss within 50 meters before hearing my character say "I need to get to the tail and use timestop to make it across". These "helpful" voice lines happen pretty often. The only good thing here is that they don't seem to repeat.

Lastly the game just runs poorly, on the second stage I'm constantly in the 40~fps range which is just unacceptable on a 3070 and a Ryzen 7 3700X.

It's a real shame, I had high hopes for this game.

Not a good game, but not a bad one either
Graphics, sound design & level design are great
As for gameplay, it's quite repetitive, even though each location adds new mechanic
Boss battles are underwhelming, its just - run from point a to point b and click lmb sometimes, boss music degrades experience further, it just doesn't fit
Some mechanics are just wired\could be done better: time stop is mostly useless, and game never requires you to utilize it
Acid works wired (i get that it's supposed to be for a faster gameplay, but there are definitely better solutions then the current one)
Sometimes camera works wired, but ig that's fine
Also world is pretty empty :(

Cul game, very unique