Sunset Overdrive

you earn badges simply by playing the game. badges unlock after doing certain moves/shooting enemies etc.- example- grinding. after you have grinded for a while you will get a badge. wall running, bounce jumping, style points etc. the tally for your actions is saved both on chaos mode and single player. they level up slowly. once you unlock a badge you can equip an overdrive ( another achievement will pop as soon as you check your badge and assign your overdrive "Unlock an Overdrive")- I was about 6 hours in when I got my first badge- in single player- for lots of bounces. after my first badge unlocked about 5 more badges unlocked within minutes.

I got my first badge grinding, however an much faster/easier way to rack up badges for Semi Auto kills is with the method I have made outlining how I got a few other kill based achievements. Very early in the game to get to, and is a nice way to grab a batch of cheevo's at once!

Hope this helps!

This is locked until story mission called Boo-Boo Roverdrive at Oxfords base. In this mission you have to recover a robot dog.
Once the mission starts, the game will automatically give you first badge (grind badge) and you use it to unlock first Overdrive as well, earning you: