If you asked me what the most important aspect of a good game was, I would have a convenient one-word answer for you- "controls". Much like tempo in music, color in painting, and sound effects in film, the right controls can vastly improve a game while frustrating controls can ruin it. It's an art form entirely to itself, and a well designed control system has considered these concepts and how they affect the user's experience.
Delay / Responsiveness - As a general idea, delay is the time between the player sending input and the game producing a result. Every player will notice this on some level, consciously or not. Zero delay is often desirable for movement and in firing weapons, however delay must be carefully chosen for some actions. A shooter will lose realism if you can switch weapons too fast; too slow and players become frozen when weapons run out of ammo. Even for 2D puzzle games, a delay is important for players to review moves they make before the game board changes. Generally, a delay should be implemented any time the player has to change their thinking and strategy; it allows a "rest" to alter their expectations and orient the mind.
Movement Speed / Run Speed - More specifically, top speed. This interacts with numerous design elements of a game, particularly level design. A high run speed does not usually mix well with hard corners and narrow corridors, and low run speeds are frustrating in open areas. Top speed can determine the amount of time between a player spawning and their first encounter, and as such it is extremely important in multiplayer action games. Changing run speed can even be treated as a strategy mechanic. In games like MMORPGs with traveling or large open areas, players will often go to extreme lengths to increase their run speed.
Movement Acceleration / Deceleration - Goes hand in hand with top speed, interacting heavily with level design. Acceleration will also affect the way players can react to incoming attacks and will change the path they take across a level, affecting the views they see. Knowing how quickly they can move, an FPS player will change where they position themselves near cover and can influence them to stay put or emerge during a firefight.
Movement Friction - Almost the same as acceleration and deceleration but not quite. Friction shows itself when a player is sliding down a slope and may also affect turning/changing direction (depending on the way movement is implemented). Changing friction on different surfaces makes for a great game mechanic, as in countless classic platformers and FPSes, particularly the Half-Life series (especially Portal 2). In the online FPS Urban Terror, a whole genre of environmental challenge levels called Icy Jumps is built around reacting on low-friction surfaces.
Vertical Slope Limit / Climbing Ability - The vertical slope limit is the steepest possible hill the player can move against before they are halted or begin sliding down. A high slope limit can prevent players from getting stuck on world geometry, but a low slope limit can increase the sense of altitude and height. The game Skyrim used a high vertical slope limit to allow players to scale steep mountains as though they were flat surfaces, allowing the designers to obscure distant views with mountains rather than an ugly clip plane, while still allowing near unilateral freedom of movement. However, Skyrim's limit may have been too high for experienced players-- I found it relatively easy to scale its highest mountains and buildings, and I could rapidly escape dangerous encounters.
Gravity - Good ol' acceleration towards hell. Simply a type of acceleration outside the player's control. It's important to note that gravity is distinct from maximum falling speed and both interact with fall damage, a very tricky thing to get right in games. Gravity can help provide the player with a sense of pace, and naturally should never be slower than lateral movement. I use the term "natural" because a designer may want their game to feel different or offensive in pursuit of a specific experience.
Jump Height - Doesn't need much explanation, but there is some nuance to it. In FPS games, a natural jump height is never lower than your crouching height or higher than your standing height (so you can charge from behind cover but not appear from behind walls). In platformer games, a natural jump height does not lift you outside the screen area (so you can always see where you will land). Typically jump height is not a value but is determined by gravity against a jumping force. Some games don't allow jumping for many reasons-- while this is realistic (how often do we jump on things in real life?), I have never played one of these games without yearning for that little bit of freedom (after all, how often do we get to jump on things in real life?).
Crouching - Another simple, pleasurable concept often missing or re-interpreted in games, crouching can be used for a wide variety of purposes. It might allow players in restricted spaces, make them harder to hit, increase their accuracy or simply reduce their speed while silencing their movement. It's a great tool, since every player inherently understands it- gaining one ability while sacrificing another. Sometimes crouching is foregone in favor of a locking cover system. Locking cover systems can allow for some effective AI behavior, but sacrifice freedom and often make me feel more vulnerable rather than less.
That's just a handful of the many factors that make up the "controls" of a game. There is no such thing as good or bad controls, but pleasurable controls are generally those that harmonize with the rest of the game. Think of a game's controls like a pair of lungs, periodically allowed to stretch to their fullest extent without feeling shallow or limited. Controls should be used to manage the players expectations and, when the time is right, to defy them. When ignored, controls are often described as "clunky", "sensitive", "heavy" and "clumsy". When done right, controls are not noticed-- but the player connects with the game, and appreciates it on a deeper level.