One Smart Cookie
Collect "the only collectable coin" in Level 2.


Post Traumatic Stress
Die 30 times in a single stage or boss. Definitely the hardest achieve, because you're way too good at this game.

Power Up
Just like the blocks of a certain other game franchise, bumping one of these present blocks from below is not only totally harmless, but spawns a bunch of delicious coins! Punch one of these deliberately to earn the achieve.

Slow Learner
Collect 1000 coins over the course of the game. Bonus stages DO count, so speed things up by running through Bonus Stage 3 a few times.

Surgical Strike
Kill a bouncing heart while standing on a springboard. Do this one in Level 8, where springboards, hearts and a checkpoint are all in the same convenient location. Keep at it until you succeed in killing a heart.

The Cake is a Murderer
Do Chell proud by falling continuously for 10 seconds.

Falling For It
The first two jumps at the beginning are unavoidable, as is a jump across the large coin pit after the first checkpoint — and those are the only three jumps you need to make. Holding the jump button as you're bouncing off a spike doesn't seem to count as a "jump". Everywhere else can be traversed by falling into pits.