Sorry it took so long, but given the fact that the stage wasn't in level select, it took a while to get to...and a while to get back to the stage whenever I game over'd. >_>
It's a good improvement over your previous levels, the flow was good, the ramps were really smooth, it wasn't ever cramped, the unlockable door worked out okay for the most part, and I liked the textures. Yet like the rest, it has problems...
For one, while randomly thoking as Sonic at the beginning of the stage, I ran through a wall and into a red block. O_o It's a minor problem though, can't knock off points for that, but still funny. :P
The path you created for the first loop doesn't always work...
It wasn't exactly the best idea to force those flying creatures(whatever they're called.) to stay in mid-air. Some of us do force Adventure mode off, or use characters that can't use the homing attack at all. I had to weaken the gravity to reach them as Blaze.
The pink switches was a neat idea, but you should reduce the number of them, and also make the switches accessible by some other means for characters besides Knuckles, Tikal, Rouge, Super Sonic, or Burning Blaze. Lots of users play as custom characters/don't like Knuckles, so it's a good idea to give your players options/alternate routes.
I don't have an image for this one, but it isn't needed.
You know the two rooms that have enemies which need to be defeated before continuing? Well, it's a great idea I think, but there needs to be a way so that the player can immediately understand what to do. (Like some marking of a broken Crawla on the ground next to the door.) You also might want to remove the Crawla Commanders from those rooms too, they can be tedious to take out sometimes.
Now besides what I mentioned, I liked both acts HS. This has lots of effort put into it.