Power ups are special items from random boxes or buying with SAS Dollars. Every item has a special effect. Here is a list of power ups with their effects and price.
Cryo grenadesEditCryo grenades freeze every zombie for a short time in small radius. You can get 4 of these from random boxes. Don't waste them on Mamushkas, the freeze effect ends if they die, so their offspring is uneffected. However, they can make the difference between life and death, especially when used on Boss Zombies.
Price: 150 SAS Dollars for 10.
Incendiary grenadesEditIncendiary grenades makes a explosion and burn the zombies for a while in small radius. You can get 4 of these from random boxes. Great for Clowns.
Price: 225 SAS Dollars for 10.
Necro grenadesEditNecro grenades make a biogenic blast that disintegrates zombies entirely in small radius but is expensive for monster damage. Some similar to the Holy grenades. You can get 1 of these on random boxes. Kills bloaters in one hit and deals great damage to Devastators.
Price: 300 SAS Dollars for 5.
MinesEditMines can be put on every place and denonates only on zombie contact making a big explosion! You can get 3 of these on random boxes.
Price: 120 SAS Dollars for 10.
Health upEditRepair kits to repair to full health all turrets, SAS and barricades on small radius but it's some expensive. You can get 3 of these on random boxes.
Price: 350 SAS Dollars for 10.
Longbow chopper will help you with MG .50 cal. and rocket support for a limited time, to be exact, around 2 minutes. You can get 1 of these on random boxes.
Price: 350 SAS Dollars for 3.
Typhoon bomberEditAirplanes leaving a lot of bombs along 2 coordinates you select for 5 times. You can get 1 of these on random boxes.
Price: 300 SAS Dollars for 3.
Is the last option when you have problems. It launchs a devastating explosion destroying all on huge radius and after leaving a lingering anti-necrotic cloud for limited time. You can get 1 of these on random boxes.
Price: 400 SAS Dollars for 3.
NOTE: Is not recommended to buy one of this because it has a glitch that the explosion doesn't any effect.