Here are my thoughts about the CS+ mod so far:
1. The diagonal in the third room should have more spikes. It seems possible to go through that area without being hit.
2. I think that this mod might interfere with the Cave Story canon. (New) people could think that the Labyrinth is placed somewhere near the King's Table, and think that Grasstown is next to the Bottom of the Island (which also holds the Ghadi), and become confused.
3. It seems unbalanced to have the Booster 2.0 be available all of the sudden. That's my opinion though.
3.5. I also find it unbalanced to have a rising platform section followed by a platforming section followed by a Last Cave-esce area followed by... etc. Again, just my opinion.
4. Something in the Tower: Stay on the center block after it has stopped and it will descend. Is there any possible way to keep this from happening (like add a layer of blocks when the player reaches the top).
5. If needed/desired, place Quote's facepic somewhere in the beginning sequence. The reason why I say this is that all of the CS+ mods use the 2x graphics (which is where the Amaya-Made(?) facepic can be found).