If you inspect each NFT tier, you will see custom descriptions that will give HINTS as to what is required to evolve to the next tier. As NQ is also a RACE in a way, because the higher tier NFTs will have a lower supply. So it will literally PAY to keep up on NestQuest as new Tiers are released.
Tier 1 > Tier 2 - To hatch The Egg, you must incubate it for 30 days on the NestQuest Board Game.
Tier 2 > Tier 3 - To evolve The Hatchling, you must stake >25 GOFX tokens on the GOFX Staking pool.
Tier 3 > Tier 4 - To evolve The Gosling, you must successfully acquire "The Orb" from the NestQuest Chest Guessing Game, and evolve it on the Altar of Migration.
Tier 4 > Tier 5 - Coming Soon!
Tier 5 > Tier 6 - Coming Soon!