I just had to register to express my thoughts on your project:
This is Sick!
It has a level of polish and professionalism to it that you usually don't find in Mod content. The Game got me hooked from start to finish, I was addicted to the ball! Yes, coming to the ball... what a lovely gameplay element you introduced here. I don't know if I'm the only one who felt like a close relationship growing between "it" and the player. "Portal"'s Companion Cube would come into mind. I found myself talking to it "Where are you?", "Look what you've done to those poor mummies!", "Are you tired?", "I know you like me, and I feel the same. But a safety distance would be advised or I will end up sticking to you like a pancake!", "What are you doing down there?!"... (no need to phone the doc, i'm already taken good care of...). Just to say how powerful such a device can be both on the player and on carrying on the story. In this hostile world it's the only companion you can actually trust, a valuable friend more so than having 20 guns in your inventory.
I could continue iterating on it but i will just bore you to death(or scare) with my ball fetish
The Puzzle elements were straight forward, I managed to solve them with relative ease. Therefore I wouldn't mind some tougher ones, those who'd give me headaches
. The mixture of puzzle and combat elements are revolving around the ball, the balance between them was done well to be honest and I didn't mind the occasional Mummy making me run for my life while I couldn't access the companio... ehh Ball XP
Ok, telling you that all's well wouldn't exactly be helpful for developers though. Would it?
About Save-System: Checkpoint based is fine. But the possibility to load a checkpoint instead of replaying the whole Level would be neat. But you said that UT3 doesn't really support a feature like this, so I don't count on it being fixed (I played the mod in one sitting though).
Puzzles... I can just see how much work and thought went into them... So I would just suggest keeping it up, they should always get a special treatment. Trickier ones involving the player to go back and forth in a Level (sort of puzzle boss) would be welcomed.
Maybe expanding the game menus, like having your own Pause Menu (nitpicking at best!)
Not much I disliked. The pace is excellent, smooth gameplay nice use of physics.
Good job, keep it up and I wish you good look for your future endeavours