A very solid "adventure hub", perfect to start a campain, but that can also be easily integrated into an ongoing one (especially if the PCs don't have a spaceship). The 3 "sky tombs" are very different (a pirate base, a relatively lightly guarded sunken tomb, and a big one where two groups fight one another). The layout is simple yet highly functionnal : the backstory and key to a 37-rooms sky tomb fits on 4 pages, plus another one for the map; all NPCs are described on a single page (another one gets you all the combat stats) with their important motivations and ties stated (useful in play to help you recall the more in-depth descriptions given before); lots of plot hooks and complications to throw at players while they are on Brightside station; etc. The background provided, both for the tombs and the station, is just long enough to be useful to a DM : the information provided is meaty enough to help playing the NPCs and improvise when needed, but not so much that you lose yourself in details and minutiae.
The only downside is that the art is very scarce : not counting the maps nor the cover, there are only three pieces, one being useful (showing an alien race), the other two, not so much. But it's a minor quibble.
The adventure provides opportunities for exploration/xenoarcheology/plunder, social interactions and combat. Better yet, altought there are plenty of hooks and nudges to implicate PCs, nothing ever really forces their hands : they could basically just stay put, pay for their stay, and watch things unfold; they could never leave Brightside and play a political/social game, or a sabotage one; and they could go explore/pillage sky tombs, letting the situation on Brightside sorts itself out. The PCs actions can have important repercussions on the station, but also the campain universe (possibly impacting the fate of two ancient and unknown alien species). While not limitless, the possibilities are many, and that's great.
I'd say that you would get at the very least 2-3 sessions out of it (beelining the tombs, not exploring nor discussing), probably more if the players take time to discuss with NPCs and explore the tombs, and even more if you make your own sky tombs using the geomorphs and background provided.
Alll in all, it's a fantastic product!