For this achievement, you will need to collect EVERY Relic and Idol in the game. There are 65 regular stages, with 3 Idols each, and 16 Relic stages, with 1 Relic each. You can progress through the game without collecting all 3 Idols on each regular stage but it is advised to stick at each stage, whilst the layout is fresh in your mind, until you've got all three. You can replay any previously completed stage at any time though, so there's nothing to stop you leaving some and coming back later. Idols appear on each stage as you gain more cash. To increase your cash you should be collecting all gems, killing all enemies and clearing all traps. Your cash is reduced by 25,000 every time you get hit twice.