Equip the Mystery Chip and complete Gear Fortress 4 to get bonus Screws. Completing the stage under a certain time limit provides double the amount of Screws!
Newcomer: Over 5:35—700/Under 5:35—1,400
Casual: Over 3:45—700/Under 3:45—1,400
Normal: Over 3:45—350/Under 3:45—700
Superhero: Over 3:45—350/Under 3:45—700