Two powerups are implemented: Haste and Damage Boost. They can be given or removed with these inputs:
SetHaste (time in seconds)
SetDamageBoost (time in seconds)
If time = 0, the effect will be removed. If time < 0, then the effect will last indefinitely until removed.
There are also powerup entities: momentum_powerup_haste and momentum_powerup_damage_boost. They both take a ResetTime key like the weapon spawner entity. The haste powerup takes a HasteTime key, and the damage boost powerup takes a DamageBoostTime key. They are both specified in seconds the same way as the inputs.