Easy Achievements
Those Achievements are self-explanatory.
Stages
The best strategy for every stage is to click mouse 1 as hard as you can and only dodge on those 2:
The green obstacles most of the times are easy to react, the blue ones are a bit more tricky, so I would always be looking to the time, and memorize at which time the obstacles appear, so if you die to one of those obstacles you can dodge the next time.