It's the best 'build shit' game out of all the minecrafts and Space Engineers, if you can work around the obtuse UI, and put some time into watching/reading the tutorials.
What makes it the best out of the genre is that there's quite a lot of systems at play. You not only design the hull of the ship, but for example also have to build a turret's internal systems (cooling vents, loading belts etc.), down to even designing what the shell is built like (AP head penetrates armor well, but the increased shell velocity makes it more prone to be deflected by enemy energy shields, you have a variety of fuse types to determine when to explode the warhead, you can build flak pom-pom ammo for AA purposes, neat stuff like that).
Same with engines, targeting/detection systems.
You always want to build your ships, especially the bigger ones, with redundancy in mind, because it's quite easy to blow up enemy ammo stores and you don't wanna place your fuel right next to that. Just gives all those cool lego blocks actual purpose as you gotta consider their price, weight, buoyancy etc., which I can't really say about Space Engineers. There's quite a lot of customization to the vehicle's AI behavior to tinker with, you can set individual turrets to target different types of enemies (even make CIWS anti-missile chaingun turrets). You can either control the ships yourself or let the AI do its thing, but there's nothing in terms of multi-ship tactics at the moment.
There's a rudimentary campaign that pitches you against different factions (fantasy ironclad-like designs, aircraft-oriented guys, hi-tech speedy laser speedboats; most of those are community designs curated by the autists over at their forums). It's getting better as they add a local resource system (you gotta build shipyards, resource-gathering ships and transport vessels, repairs take time and resources, fleets burn fuel which needs to be refined and transported), but as everything else in this game, it's hidden behind an obtuse UI.
Quite monocled for what kinda game it is. I don't forsee it being a hit because it lacks reddit-approved mascots like KSP, but it's easily on KSP's level of complexity already (and to me the warfare aspect adds actual purpose to the designs).
