Here is the full list of all 20 Top Run achievements.
Play 1 game
Save a friend
Save 42 friends
Complete 25 objectives
Complete All objectives
Visit Buddy Time
Survive your first lava floor
Get a new skin
Purchase an upgrade
Upgrade everything to the maximum
Run a marathon's distance
Meet Night Driver 90 times
Reach level 27
Run 1.5 miles in one run
Kill 1,000 enemies
Destroy a Prism
Beat top score in Cybervaders
Play 15 games dressed as Thriller Kevin
Collect 64,000 pixels
Run 5 miles under the rain