The Food Run

Arrows are introduced around halfway through the game and show up pretty regularly throughout the rest of the levels. Hitting an arrow for this achievement involves passing through it in the proper direction. There are a lot of arrows in some levels, so there is a good chance you'll unlock this naturally while doing everything else. If not, the best level to grind arrows is level 4-1. As soon as the level starts, go right to collect 8 arrows, and then reload and repeat until the achievement unlocks.