In the topic of abilities, Damage Up and Defense Up have been completely removed from the game. This was probably done to make weapon performance consistent. Quick Respawn was heavily nerfed, now only working when your K/D ratio is negative. Stealth Jump was nerfed as well, it now only makes your jump invisible from a certain distance. Ink Resistance is a stackable ability now.
The ranking system has be overhauled, now you don't get "points" per se, you fill a bar as you win games. It won't deplete if you lose, but several losses will result in cracks appearing along the bar. If you get 4 cracks two things can happen: if you haven't reached the "OK" range (marked by a line), you will be demoted to a lower rank. If you're past that point the bar is simply reset and you keep your rank. If you manage to rank up without any cracks in your bar you can jump as many as 3 ranks (i.e. you jump from C- to B-). Also, even if you reach S+ you can keep filling the bar, every time you "rank up" a number will be added to your rank (S+1, S+2, S+3... until S+50). However, only you can see the number and it doesn't affect matchmaking, it works like a "safety net" of sorts when you're demoted.
The Rainmaker now works differently, instead of a single giant ink tornado it sends out a blob of ink. If it's fully charged up, the blob will function as some sort of grenade and will explode shortly after it touches a surface.
In Tower Control, tracks are much shorter overall, but now you have to go through checkpoints where the tower will stop completely for a set amount of time. Once you've gone through a checkpoint once you don't have to wait there again.
There's also the new features for unscoped chargers and rollers. Unscoped chargers can hold a charge for a short time while swimming and unleash them instantly when you go back to kid form. Rollers now have a vertical flick (used by jumping first and then flicking) that goes farther than the horizontal flick, but they're narrower and the range for a one hit splats is trickier.
