First off, I'd like everyone to know that I've been a Fallout fan since the '90s. Thanks Bethesda for giving Interplay's old franchise your best! You've done great.
I especially like the title Fallout Shelter in that management sims are among my favorite genre of game. That being said, it could use some depth; which is the subject of many a criticism of the Shelter game.
We can start by adding missions. Just a thought. Send one or a group of dwellers out to some random series of mini-game levels with Pokemon-esque battling.
Perks. Nuff said. Dweller perks; vault level perks and experience could be gained by aggregated dweller experience.
Armor perks and set bonuses. Add armor slots. Awareness for mob health bars (armor bonus), healing (medic armor, room bonus, vault bonus), +1 dweller to room (leadership) are among the examples.
Anyone else think these are good ideas?