Full list of all 23 GET THE GEMS achievements.
The base game contains 16 achievements, and there is 1 DLC pack containing 7 achievements.
Run out of time
Look at the credits
Finish Cave 1 and keep playing
Kill 111 monsters in one game
Detonate 99 Nitro Bubbles in one game
Beat Cave 4 without killing a crab
Find the Secret Cave
Beat the final Cave
Kill a monster with a gem
Walk 5000 tiles in one game
Enter a valid Level Code
Finish Cave 1 in less than 30 seconds
Beat the first 4 caves in a row without dying
Beat Cave 23
Collect 131 gems in Cave 5
Reach a total Cave Score of 88888