I tried to optimize the loading, by first loading a map, displaying every object, and shader for couple of frames (thats the stall at 20%), then loading the main map (80%), and the player automatically looking around to make sure all shaders are loaded (100%). Also the game purposely stalls at 67% :). Even after all of this i do still feel lags during gameplay, that's probably web limitations - you can download the desktop version, it performs better.
If the mouse isn't captured it will recapture after pausing so you just need to pause and un-pause ("esc" or "p").
There is already an objective, just the main goal is missing and some other features.
As for the objective, you need to ship servers together, judge whether disk should be destroyed or shipped. For more details refer to my reply to 11BelowStudio comment.