I finally managed to fight through the constant connection and loading screen errors to play a mission. The core gameplay seems solid and very promising, but everything surrounding it is alarming. Even once you get past the technical issues, I quickly found the best way to survive combat was to simply fly away, and none of the enemies seemed to have any capacity to chase or catch me. In a game with flight and pretty cool abilities on relatively low cooldowns, you'd think that enemies would be hyper aggressive and force you to do some crazy Top Gun stuff, but there's little functional difference between grunts on the ground and the large turret emplacements the game seems to like. Hanging back and plinking away with longer range firearms seemed safer and hardly less effective.
I also had numerous issues with the UI (both in menus and during gameplay), you walk very slowly through the hub area for no discernible reason, and large enemies have shields that recharge annoyingly quickly (probably to combat hit-and-run tactics, but they did enough damage to me that playing aggressively against them didn't seem viable; it was more about waiting until I had several abilities off of cooldown to hit them with all at once). The loot seemed decent, but it's hard to tell in such a limited demo how it'll hold up long term.
The elevator pitch for this game is such a strong idea, in my opinion. An ARPG but with flight. But despite really wanting to like the concept, and feeling positively about the gunplay, abilities, and gameplay loop, the game's design seems pretty bad and the technical state the demo released in is absolutely unforgivable. Frankly, I don't think this will be the bomb people in this thread are hoping for, but rather more of a disappointment that'll just be generally crappy. The sort of game you'd play for 10-15 hours, enjoying a bit less each session until you just sort of forget about it because it never truly grabbed hold of what it could be. Maybe patches will eventually turn it into a legitimate competitor to Warframe, but it even getting that far would require it to do well financially. The first impressions the demo is giving people are doing their best to assure that won't be the case.