I clicked on a bounty for the first time and it said type: normal and all of the current bounties were "normal" so does that mean you just have to finish the game? will there be completion bounties?

The bounty type is more or less just a placeholder for potential future....stuff. There are actually two options: 1) Normal; 2) Pilot. We used the "Pilot" type for the first month or so when the bounty system went live and then switched over to "Normal". I could see adding a "Speed Run" type or maybe a "Custom" which could include some additional instructions / requirements, but not really sure yet :)