This setting is the most wide-ranging in its influence, as it affects the speed of animations (jump shots, dribble moves, shot contests, low post moves, ride-the-hip animation, etc.), the speed of the ball in the air, as well as the speed/fluidity/weight of players with the ball.

That last part is most important, as many have complained about players feeling "floaty", sliding around the court, and not feeling like there's any weight involved. The Game Speed setting is the culprit. At higher settings you'll get more explosive animations, sure, but you'll also have players gliding around the court like it's an ice rink. With lower settings, animations aren't quite as explosive, but players with the ball finally feel like they're walking/running instead of skating, with the added benefit of allowing the game to trigger more context-based animations (dribbling in traffic without the game ignoring the on-ball defender).

"But Eccentric, we have the Speed, Acceleration, and Movement sliders, so why does Game Speed really matter?"

For that answer, continue reading...

Now these are the sliders you would THINK control everything movement-related, more or less. And in a way, they control what you'd expect them to. BUT, they don't control all movement equally. Let me explain.

There are two versions of movement: with the ball, and without the ball. The Speed and Acceleration attribute sliders DO control both, but not anywhere near equally. If you set either one to 0, you'd think the game would feel like everyone is stuck in the mud, but give it a try and you'll see that's not the case.

With Speed and/or Acceleration set to 0, you'll notice that movement without the ball is affected as you'd expect, with players moving at a snail's pace. HOWEVER, you'll also notice that movement WITH the ball is barely effected. What??? That's right: The Speed and Acceleration attribute sliders have a huge affect on the movement of players without the ball, but a very minimal affect on players while they dribble.

Lateral Quickness controls the speed at which players can pivot and change direction (only noticeable on defense or playing off the ball, not while dribbling), so think of this as the "turn the corner" defensive slider. If this is set low the player with the ball can just walk into the defender and the game will trigger a blow-by animation, no change of direction or dribble move required. With this set high the defender will stick with the ballhandler and the game will trigger a "ride the hip" animation or a "brick wall" animation. If it's nearly impossible to blow-by any defender you'll want to set Lateral Quickness lower. If you can blow-by Kawhi, you'll probably want to set this higher.

Non-surprisingly, these are the most straight-forward sliders of the group. These sliders are all correctly labeled in a common-sense way, and they simply affect the difference between the fastest and slowest players. You want the quickest players to really stand out? Increase the Max settings. You want slower players like PFs/Cs to still be able to move NOT in slow motion? Increase the Min settings.

"OK Eccentric, thanks for the essay... But I'm not a college professor, I'm a slider guru. Can you break this down so I can tweak the game to play the way I want it to?"

Alright alright, so I got a little wordy here, but I'll summarize it as best as I can and lay out a series of suggestions:

In the simplest terms, the Movement sliders set the Max and Min speed/acceleration of players on the court, and then the ACTUAL movement speed/acceleration (i.e. how fast/slow overall player animations look and feel) is controlled by the Game Speed setting (for ON BALL movement) and Speed/Acceleration (for OFF BALL movement).

Lower Acceleration = more weighted movement, as you won't instantly snap to full-speed. Lower Speed = more realistic movement, stopping the game from looking like it's in fast-forward.

Suggestions

For more realistic, responsive, and explosive animations (step-backs, shot contests, two-player animations when driving to the rim, etc.) - Increase the Game Speed setting. The higher you set Game Speed, the faster animations will play out.

To make players with the ball feel less "floaty" and more weighted - Decrease the Speed/Acceleration with Ball (Max/Min) movement sliders. Start with your fastest players by just tweaking the (Max) settings. Once you're happy with the look and feel of dribbling with fast players (Harden/Westbrook, Lebron, Kawhi/PG13, Kyrie, etc.) give the ball to your slowest forwards/centers and increase Speed/Acceleration with Ball (Min) until they are no longer moving in slow-motion.

To make off-ball/defensive movement feel less "floaty" and more weighted - Decrease the Speed/Acceleration without Ball (Max/Min) movement sliders. Start by controlling your fastest players and running around on defense. Tweak the Speed/Accel without Ball (Max) settings here until these fast players move and feel the way you want. From here, run around with your slowest forwards/centers and increase Speed/Acceleration without Ball (Min) until they are no longer moving in slow-motion. (I recommend setting the Max settings somewhere between 70-80 so the fastest players can stand out, while setting the Min settings to somewhere between 50-60 so slow players can still close out on shooters, protect the lane on help defense, and maneuver around the court realistically.)