I am done with the demo missions and checked into Freeplay (roaming the overworld) this morning ... Still have not unlocked another Javelin other than the Ranger (but I've seen the Interceptor and the Storm in the wilds)
Network issues got better this morning; but the whole thing did make
headlines for just how little infrastructure they had for the demand.
The missions actually get better once the opposition evolves - the Dominion are just stock human-enemies with the odd enemy javelin in there (same goes for the Outlaws you meet roaming); the Scar are actually a bit more challanging with Snipers those rifle kick you out flight, Grenadiers that force you to keep moving, and
Brutes Enforcers with big shields you almost have to be in team to take down (hitting the shield does 0 damage but when you get around you can shoot some weakpoints for extra damage); the Elementals are a bit in-between with smaller ones being like stock beasts, but the Titans actually need some awareness so you don't pump them full of bullets to no effect (Titans get vurnable spots when they charge their attacks).
Freeplay is actually more fun than the missions, although I wish there was a bounty board or something to structure it - right now you just go out, shoot some stuff you come across, loot ressources and gear, and do your challanges for XP. "World Events" are actually cool but I found they can't be solo'ed; a boss fight with roaming Luminary with another Ranger I happened to run into was particullarly fun (though we went down around 50% mark)
What detracts from the experience is that I frequently ran into "Leaving Mission Area"-borders when just flying around... again, maybe just a restriction of the demo content or me hanging around in the wrong areas.
I will get on today and tomorrow and see if how the dungeons play and try my hand at the Stronghold-group mission.
EDIT: Just saw a Collossus during Freeplay ... for 5 seconds, then he pulverized an outlaw camp with his mortar and jetted off
Also just got mangled by an Ursix during a world event, aka "the reason you will be glad for your ability to fly" - due to event's victory condition I has to put my feet on the ground and got cornered.