Sifu

To even be eligible to earn this achievement you MUST acquire at least 20 stamps to have access to the first 25 arenas. Stamps within Arenas are earned through accomplishing either time, score or age constraints within the given challenge and you can earn up to 3 stamps per arena.

Now the good news: you do NOT have to earn a stamp to have a challenge get counted as "clear": you simply need to complete the challenge without permanently dying (either by dying at age 70 or sometimes by other means such as falling off of the map).

I would still recommend trying to earn at least one stamp so that you can continue to improve your capabilities on the path to the tiger clear and 240 stamp achievements.

Below is a a video that shows gold clears on each map so you can get an idea of how to approach each map although I should warn: Attempts at emulating the video will do little if you do not have a firm grasp of the games mechanics


edit: credit to the video goes to iconoclast on youtube!!