Crash Bandicoot N. Sane Trilogy

When u final thegame u get an abbility to run.
Only repeat the first ten maps with this abbility and u can get all in gold so easy.
If u can get a platinum relic u can count it.
Repeat and when u get the firts ten relics pop the achievement

As noted on the guide for 30 relics (from superjek):

You'll have to practice levels again and again to remember how to avoid traps, enemies and danger, and also remember where are the time bonuses. This is especially important with bike, where you can't get back, and boat, where performing a U-turn would cost you a few seconds, consider skipping it and continue.

I recommend the following levels that are doable (even with my poor skills).

• 1: run on the walls on left and right, to avoid enemies or water (it slows down)
• 3
• 4
• 5 (boat)
• 6: like 1
• 11
• 15: like 1
• 18 (boat)
• 22 (bike but easier than the other bike levels)
• 26 (boat), use the elevator in the middle of the game hub to reach this level

Video guides can be found here: Solution for C3 | Boo-yah, Grandma! Boo-yah! In Crash Bandicoot N. Sane Trilogy