Here is the full list of all 6 MythBusters: The First Experiment achievements.
We lifted a chair with balloons, but can we lift an entire house!?
Travel 1000 m (3280 ft) by a baloon chair. You want to know what's at the end of the ocean this badly?
Using your balloons, fly above 130 m (426 ft). Tons of balloons well spent?
Cut 5 consecutive perfect saw cuts in a row. I wish you were working in my woodmill!
Create 20 usable mixtures in the Pumping Station.
Blow up a grenade, because that's what grenades do.