Armored Core: Silent Line:
Get Bonus Parts 
To earn bonus parts, get an A or S on any mission. 

Get Defeated AC Emblems 
To get Emblems from defeated ACs, press START+SELECT when the victory slogan appears. 

Overboost 
To boost faster press both L3 and R3. You should boost forward at twice the normal speed until you run into something. However, you can not stop until you run into a wall or other object, so there is risk of using all your boost.