your face and frills are so weird
shading in the eyes isn't helpful here
you messed up big time on the shiny swap
your best argument is height, but yours just looks cramped now, size is relative
see: Mienfoo and Vullaby on looking away
The frills on the front sprite are the exact same as the ones as those of the original sprite - the back sprite frills are simply angle up more. Not really sure what is meant by "weird", but I can try to touch it up some.
I can see what you mean by the eyes not necessarily needing to be shaded - that's an easy fix though.
I'm not exactly sure what you mean by the shiny swap, though. I didn't even include a shiny Heliolisk for my take on Heliolisk - I simply took what was in the Google Docs to give a side-by-side comparison. Other than that, the color pallet is the exact same.
Height is relative, sure, but within the context of family Pokemon, Heliolisk is huge when compared to Helioptile. I feel there should be some sort of similarity in sizing when it comes to Pokemon families, as well as taking the general size of the Pokemon into account. The current Heliolisk is nearly the size of Beartic, who is a 8'06''. Again, I know size is relative, but keeping Pokemon families consistent is my goal here.
What about the sprite is cramped, though, if you could be more specific? Is is in the torso with the frills and arms, or some place else? Because the pose is basically a shrunken down version of the original pose, with the same amount of space open in his stomach/torso relative to the original counterpart, I'm having difficulty finding where exactly the cramped spacing is.
I completely disagree that Vullaby and Mienfoo are looking away from their opponent. Mienfoo's head is tilted more diagonal, but his eyes are still facing towards his opponent. And Vullaby's facing straight ahead. Unless you meant Mienshao and Mandibuzz. I'd argue that Mandibuzz is still facing the opponent - it's hard to tell in the spritework, but seeing that the artwork is basically identical in posture with the sprite, you can see that Mandibuzz's eyes are just closer/being covered partially by its eyebrow. For Mienshao, I'll concede that he's not facing directly
at the opponent, but he's still facing in the relative direction of his opponents surroundings. The current Heliolisk sprite is simply looking in the air, completely separated from the battle field.