CHARGE should be a very familiar mechanic to us by now. Since the NES, with games like Mega Man players have been able to charge their attacks to make their next shot more powerful. More specifically, the CHARGE mechanic only applies to cases where a move's strength, speed, or other positive property can be augmented by not using the move for some period of time. Some moves get a wider range (Mega Man X). Some become slower but home in on enemies (Star Fox 64). Some moves gradually get more extravagant the longer they're charged (FF6 Cyan's Sword Tech, Secret of Mana). Others require a move to be charged to activate it in the first place (Halo's Spartan Laser). Whatever the game, the weapon, or the situation, the CHARGE mechanic is quite genius in how it develops flow, creates momentum, and effectively punctuates negative space while giving the player the ability to adjust their own difficultly level by relying on knowledge and timing. Let's look at an example.
In Mega Man X, there are 4 different types of shots with 3 levels of charge. The standard shot is very small. All damage is quantified by this attack. Though each bullet only does 1 unit of damage, this shot can be fired about as rapidly as the player can push the fire button (faster than 13 shots per second). This attack is only limited by the player speed and how the game is limited to displaying 3 shots of any type on the screen at any one time.
The green shot does 2 units of damage and travels at the same speed as the standard shot. To charge, players must hold down the fire button for approximately .6 seconds and release.
The blue shot does 4 units of damage and travels slightly faster than all other shots. It takes approximately 2 seconds to charge.
The pink charge is a devastating attack. By doing 12 units of damage from a 3.5 second charge, for the additional charge time, this attack triples the damage and the range of the blue charge shot.
In my experience, I use every type of charge in the game. Unlike other games where the most powerful attack strategy is used in every situation to efficiently progress (RPGs - attack-attack-heal), the 4 levels of shots in Mega Man X are balanced by time and space. The rapid standard shot is most effective at close range and on stationary targets. The green and blue charge shots are effective on most targets, but the player must sacrifice time to build each charge. However, because shooting and moving are directly related (ie. Mega Man can only shoot in the direction he's facing) there will naturally be times where the standard shot would be completely ineffective as the player is dodging, getting into position, or aiming.
Because the blue charge shot is slightly faster than the standard shot, it's possible for the player to hit targets that the standard shot would not be fast enough to reach. And finally, the pink charge shot takes the longest to charge but does the most damage of any single shot. Though this attack is large and travels at the same speed as the standard shot, it takes the longest to active upon releasing the fire button. This slightly changes the timing needed for aiming unlike all the other shot attacks. Using the pink charge shot involves the most risk-reward out of all of the shot attacks. As the charge time increases, the pressure on aiming increases. After all, in the world of gunplay, victory and death are both either hit or miss.
By investing in a charge shot, players put more weight into hitting the target with their next shot. To successfully land a charge shot, players have to rely more on their knowledge of their enemies and environement.With spamable unlimited rapid fire attacks, aiming is less emphasized because there is no penalty or drawback from filling the screen with bullets (especially if there isn't a limit to how many bullets can be on th screen at one time).
Look at this green enemy for example. As you can see, all shots are ineffective on all spots except its head. The only way to hit the head is by repeatedly jumping and shooting. Because the enemy claw attacks is so predictable and avoidable by jumping, the advantages gained by charging are diminished. In other words, the time it takes to charge and fire just about equals the damage players can inflict by repeatedly jumping and firing standard shots. Because this enemy has so much health, and the strategy doesn't change even when the battle speed increases, this battle contains a lot of negative space.
For most bosses and enemies, the increased range and damage from charge shots offers strategic alternatives to the player's offensive approach. Due to Mega Man's solid platforming elements, dodging attacks, jumping over enemies, and moving through the environment naturally creates opportunities where it is advantageous for the player to start charging. In the image above, when Mega Man jumps over the missile or the electric balls, the enemy is ducking too low for a standard shot to hit. In this situation, charging a shot turns the negative space where the player would have to wait into positive space by investing in the next attack opportunity. So, as the the player moves through ever changing situations, the advantages and difficulty of the different shot strategies changes dynamically.
MegaMan is just one game series that has nailed the CHARGE mechanic. Let's look at some others.
That covers the CHARGE mechanic. Many games have used it well, and there are still many that could benefit from incorporating the CHARGE mechanic to help them reduce clutter and negative space in their core design. Geometry Wars... Everday Shooter.... I'm looking at you. More on those later.