You need to complete 20 levels in a row without dying. Luckily, they do not need to be different levels, meaning you can play the same level over and over again to earn these achievements. Level 2-1 is best for this achievement. Just load up the level and keep completing it. It only takes about 10 seconds to finish the level (ignoring collecting the blobules), so your should knock both of these achievements out in just a few minutes. Be sure you hit the restart button at the end of the level each time when it pops up. Do not pause and restart or advance to the next level as it can reset your progress towards 20.