The tower idea is well transmitted, the prison is a good start.
Many tough parts. I died a lot. Exploration is easy, though.
Good, complex and numerous!
Long but linear.
You can start by another tower, but I guess it would be pretty the same, there are no subquests, secret areas or independant zones to explore.
Amber has clearly an excellent skill at dmuting.
Good, except for the pit thing, and hard. Though the end is classic, it happens at a climactic time since you have to go through the 4 towers before reaching it.
With more furnitures and texts, and a storyline, it could be improved. It's still very immersive.
This is undoubtely the masterwork of Amber (for now).
The layout is "intense" (there's no empty zones), the 4 towers idea is masterfully designed. The traps and puzzles are legions. I liked the Battlefield!
Entering pits to finally find a key, the monster generators are sometimes tiring. Several keys are useless, is it on purpose?
This dungeon is a model for good balance. The difficulty increases progressively, the weapons and armor are hard to find, the water level must be watched. Only the food is overabundant.