I just saw there is a demo/beta and new vid (but I'm at work atm so look at anything yet), but it reminded me of a thought I had watching one of the extended play through videos that came out a bit ago.
I was thinking that I was really bothered by how the characters were jumping and in general getting around the levels. It definitely fit in with the side scroller genre, but for some reason it seemed out of place with how the game world is represented.
I thought that more fitting movement style would be the kind you saw in flashback, out of this world, black thorn, and/or price of persia. Not 100% that, but more towards realism. I'm having trouble putting to words what I mean here...
Have the characters really have to work to get to a location. If I come up on a cave with a sharp drop, I would have to hang off the edge, or perhaps have some climbing gear or a rope I could put down and rapel down. A quick select it, fire it into the ground, and go down at a slower rate of descent. You could only jump so far (and this could be tech/magic upgrades that can launch you farther), or fall so far without taking big damage.
Really what the thought was, was the game looked like a sort of smash and grab. You pop in, fly all over the screen heading towards minibosses to get when you want and gone. You don't ever really take note of the procedurally created environments beyond where is the next exit I need... you never seem to have to stop and say how do I get over there?
I think what this would do is sort of connect you to the terrain more. You would appreciate the difficulty of getting to the bottom of a chasm that has an 8 screen drop vs just a shallow cave.
It is probably too far along to change this up... it would require altering the terrain generation to avoid places that are just too hard to get from point a to point b. Enemies might have to be spawned more carefully not to have them knocking you back when you try a difficult jump etc.
Though I have this huge nagging feeling that a few more movement options that keep you closer to the ground and have to have you think for a bit about traversing the vertical (up or down) would make the world feel more immersive rather than just blurring past like mario brothers.
It could also lead to a whole set of upgrades, either in mechanical or magical that allow you to more easily move through certain terrain areas or just in general (jump boots, slow fall spell etc) .
Again the idea here is to make you take note and see where the engine decided to place that drop off, and how far down it is, or how high up that vertical climb is. It even might lend itself to places that have very few enemies spawns but is designed to create challenging environment to traverse to grab your upgrade items.
I just wanted to toss that idea out there for consideration. I will definitely check out the game further when I have a chance, though I am guessing its state is somewhat similar to the last extended dev play through.