Just that, and if you can, give players the ability to roll a reward once a week, similar to the casino or the elevator roll with the chance of getting a shadow or silver key :)
Bring Back Gate Construction
Adding onto what Dahall said which was certainly true, the main reason people actually used gate construction was to influence the types of materials they could find. Ever since missions were added, we've had instant and easy access to any material we could ever want. The game has changed too dramatically for this to ever be a worthwhile venture.
The mineral imbalance is a problem, they ought to add corresponding sprites to sink valestone and moonstone into, and give it time for the mineral/sprite food economy to reach a new equilibrium. Then I'd say yeah, bring it back, it was a cool, unique system that gave players tangible influence over the world and played into the lore of the planet being a giant machine that needs materials for power and maintenance.
The Gate construction as it was has two issues with the current state of SK:
- Since the introduction of the Battle Sprites™, Crimsonite, Dark Matter & Luminite became more demanded due to pet food that requires their respective mineral, this resulted in Valestone & Moonstone dominating the gate construction contributions, leading to an era where the arcade became dominated by particular themes only (I remember the complaints about poison theme)
- Low player count might negatively affect gate variety, though this may be solved with number tweaking or even using a different algorithm for determining resultant theme.
I don't see gate con. returning with the mineral imbalance.