
The room in the upper-right has no gravity.
The room in the lower-left, has another instance where the Dash 2 is very difficult to use - the ability to line it up properly midjump is very tricky, and generally seems to require patience and lots of button-mashing. When you're trying to dash through a column to a hole on the far side that is
higher than one tile, it generally makes entering the column simple, as your gravity causing you to fall gives you a range of vertical coordinates that match up to activating it. Whenever the far-side space is only a tile high, however, the window seems to be pretty much limited to single-pixel precision - so if you cannot lock your Y-position (by standing on the ground next to it) the changing Y during your fall makes it supremely difficult to hit that window and enter/pass through the column.

Example of breaking blocks with spin attack. Gets me stuck in blocks sometimes scrolling rooms left/right in this area, gets me stuck in the top row of the rooms below when I break the blocks along the floor.

Inside the cave room (on the right) are a number of invisible solid blocks.

Looks like it's missing a tile in the upper-right corner.

These warp tiles do not warp you.

These warp tiles all warp you to a no-gravity/empty cave. The 1x2 crystal on the right side is not solid - you fall through it.

The bottom center warp tile does nothing. The rest of the warp tiles warp you to another no-gravity/empty cave.
Furthermore, the room above this seems like a pointless dead-end? It just warps you back to the beginning point.
Okay, I'm inferring from the level design that these sandblocks are
intended to be destroyed with the spin attack, but... they seem to make tiles around them destructible as well, regardless of whether or not those blocks are solid combos or empty spaces. Destroying adjacent solid combos removes them, destroying adjacent empty spaces just displays the explosion graphic for a bit. Here it blew another hole open to the room border (which I guess, at least I know this is the left edge of the map now, lol!)

So, you need to tweak those tiles so they stop destroying the ones around them, as well as swap out the bottom row of destructible blocks at the bottom of the underwater maze with something non-destructible.
Also, the Grappler 2 attaches to everything,
including empty space along the room borders, which seems... odd.
The large enemies' death explosion sound plays when I
enter a room with them - not sure if it's doing that every time, or just when I return to a room where I've previously killed that enemy (or enemies.) It also plays the sound properly when I destroy them. They also frequently produce a noticeable graphical glitch where they briefly appear at their starting positions after killing them, but then quickly disappear.

I get stuck in the destructible block on the top row when I fall back down this hole. Can't jump to spin attack out of it.

This cave has nothing in it. Also, it has the same invisible blocks as the other one does. ETA: The other two caves I found further along also had the same arrangement of invisible blocks in them.