Just saw your game on the itch.io channel. Congrats on being featured!
I haven't had the chance to play the demo yet. (to be fair, also Linux, lol)
But just looking at the footage on the feature video and your devlog, I have a few remarks...
First of all, the art is absolutely gorgeous! Also I can tell you've put a lot of effort into giving a lot of depth to the movement options available.
Having the weakest enemy in the game require two hits to kill is a bit bold from the perspective of a new player learning the ropes, but at the same time it depends on your target audience, and I see it introduces the combo feature which is cool.
Honestly the major gripe I could see myself having while playing this game is the aurascope build mode. It seems to take away from the flow. While watching the itch.io feature video, I noticed that the player started to jump in mid-air and then use the build mode to place tiles directly beneath them. Which made me think... why not just have that the default build mode? Have the aura cubes materialize directly beneath the player's feet, and save the mode switching for when precision is really needed. Maybe when crouch-sliding with the build key, you could materialize a bunch of cubes beneath you at once as you move.
It might even be possible to add a "flow" option to the bombs as well, with a parabolic trajectory. The trajectory could be displayed in the world. Perhaps the parabola varies in size periodically as you hold down a key. (also, I'm assuming you're trying to avoid using the mouse?)