Unlockables
     Unlock  these  extra  options by collecting collecting the hidden 
Art  and  scaning  ghosts/objects. You can turn them on and off at the 
Options  screne  (they'll be turned on by default when you unlock each 
one).

Equipment Strength Upgrade:   Collect all Art

Faster Health Recovery:       Collect 50% of the Art

Gozerian Rookie Outfit 
(Immune to Sliming):          Beat the game on Gozerian (Hard) difficulty

Increased Scanning Speed:     Scan 50% of ghosts and/or scannable objects 
                              in the game

Invulerability:               Collect all of the Art and scan data 
                              and beat the game

No Equipment Overheat:        Collect all scan data