Powerups

Powerups are pickups that are dropped by Enemies and some boss phases. They appear as glowing yellow, blue or red orbs (for Accelerate, Shutdown and Firepower respectively).

If left on the ground, powerups will cycle through the colors slowly, from yellow to blue to red, then back to yellow, and so on. The color changes every 5 seconds.

A powerup's starting color depends on the time that it spawns at. You can imagine a powerup as cycling through its colors in the background before it's spawned. The order of the color changes is the same, but five times as fast (one change per second). This allows you to control powerup color if you can play very consistently.

Powerups drop after a set number of enemies are defeated, after which the next enemy not over a pit or an island will drop a powerup when it is destroyed. No more than 3 powerups can exist at once, although progress towards the next powerup can still be made, potentially allowing multiple powerups to spawn in a short time if the existing ones are all collected.

Unlike Batteries, powerups will not block transitions within a stage and are immediately destroyed if the stage places a wall or pit at their location, or isolates the powerup from the player (such as being left on an island made just for turrets).

Spawning algorithm
Powerups spawn every number of kills, using something similar to the battery scoring system, the score value of each kill doesn't appear to be important. The kill quota and occurrence of the first powerup varies between levels. There is also a minimum time allowed between powerup spawns.

Powerups will never spawn on isolated areas or over pits.

Powerup choice for Bosses
Since Firepower gives you 600 damage over its duration if used properly, it should usually be the priority choice. It is especially useful against Vespula's wasp phases. The best time to collect it is immediately after a boss phase begins and becomes vulnerable.

In singleplayer, the 50% extra damage you can deal over a Shutdown's 2.25 second stun duration will never be as much as Firepower can give you over its duration, but it has many useful properties:


 * It will heal you if you are on low health.
 * Boss melee attacks are disabled during the stun, so you can walk inside or through them (except for Medulla, who cannot be walked through).
 * The invincibility allows you to quickly make your way around without worrying about being knocked down (particularly useful during Venom)
 * The extra damage can let you end a boss phase quickly before it can produce a difficult attack pattern.
 * Unlike other powerups, the damage bonus effect scales with the number of players. Shutdown is 4 times more effective in 4-player.
 * Additional spawns will be delayed (eg. Justice fenceposts, Medulla nodes and towers).

Accelerate is rarely preferable over other powerups except for when fighting Venom, where you might have to make your way across the arena quickly to destroy targets.