After watching a couple of videos showcasing Gravity Well (read: about twenty. Several times over.) I'm now more or less aware of how it works. It's another stun Plasmid, able to affect multiple enemies and use the environment to its advantage. As such, the two main points here would be to expand its range of abilities and make it, well... not as insanely powerful as it is now.
Changes: Rather than stunning enemies for the entire duration of its effects, they'll be momentarily thrown to the floor, after which point they'll still be rooted to the spot but will be able to attack. Large enemies such as Brute Splicers and Big Daddies will be dragged towards the singularity, although they won't be stunned. On the other hand, enemies take more damage if they hit or get hit by physics objects or other enemies. Firing the Plasmid directly at an enemy will cause them to become the singularity, attracting all nearby enemies and physics objects towards them.
Gravity Well 2 Upgrade #1: Gravity Rip. Enemies take damage from the Plasmid itself, much like with Gravity Well 3 in Minerva's Den. Unlocks Gravity Well 3 upgrades #1 and #2.
Gravity Well 2 Upgrade 2: Feedback. Every object and enemy caught in the Plasmid's gravitational radius are thrown away violently at the end of its effects, taking damage if they hit anything and dealing damage to any enemy they hit. Unlocks Gravity Well upgrades #3 and #4.
Gravity Well 3 Upgrade #1: Pull. Aiming at an enemy, holding the Plasmid attack button and dragging your cursor/controller to another area will cause the enemy to be violently pulled to that location, receiving damage if they hit anything. While under these effects, the enemy will be immobile but can still attack. Can pull enemies towards other enemies too.
Gravity Well 3 Upgrade #2: Meld. Holding the Plasmid attack button and releasing it causes all nearby physics objects (including corpses) to be dragged to the targeted area, forming a ball of junk (not exactly like the one in Bioshock Infinite, though, since the objects don't melt). The ball can be picked up and thrown with Telekinesis (With the Heavy Mover upgrade if the ball is too big). Ball will collapse if not thrown after a while.
Gravity Well 3 Upgrade #3: Implosion. Holding the Plasmid attack button creates a continuous Gravity Well at the target area, draining the player's EVE in the process. Moving the cursor/controller also moves the singularity, which explodes upon releasing the button.
Gravity Well 3 Upgrade #4: Bullet Sponge. Gravity Well also drags any nearby enemy shots and projectiles into it, releasing them explosively at the end of its effects.
And that pretty much does it. How do you like it?