On stage 1-3 there is a sledgehammer crate followed by an influx of enemies. Switch lanes and hanmer the A button. This has the best range and can kill enemies from a distance safely,even the exploders. Here is the pattern:
Bottom lane has one enemy then switch to the top lane, 3 enemies in front then one behind, middle lane one enemy in front, switch to bottom lane three enemies in front the one behind. Ten enemies and the achievement will pop. I hope this guide makes sense as it is my first 😀