Hidden elements make the game have more restrictions, Or Help do other various things. Turn them on by going to "Elebits notes" in Extras mode.

Effect - Code

Alpha Wave Unit - Beat 15 Missions in Challenge Mode
Aroma Unit - Earn the Title "King of Surveillance" after beating the last boss.
Berserk Elebits - Earn the Title "King of Capture" after beating the last boss.
Extreme silence - Earn the title "King of Noise" After beating the last boss.
High power mode - Beat the third boss. Then watch the Cutscene at the beginning of the next level.
Limit Release(Strongest level Capture gun) - Beat 25 Challenge Missions.
Main unit only - Beat 5 Challenge Missions.
Permanent Homing laser(Deactivates Vacuum laser) - Beat 20 Challenge Missions.
Permanent Vacuum laser(Deactivates Homing laser) - Get 25 S ranks in Normal Mission.
Worn Capture Gun - Beat 10 Missions in Challenge Mode