Warning #1: If building ships and then flying them is not your thing and you're looking for a more linear/on-rails type of game, then this is probably not your thing.
Warning #2: This is not a space dogfighting simulator or a replacement for Star Citizen.
Warning #3: This will let you build a great many types of ships and then fight in them. Don't expect much else. Due to the lack of other games that let you do this as extensively as KV does, I will still recommend this game despite many of the flaws.
The 'Build' here means the ability to build your own ships. As far as I know (so far) you can only build your own ship, not structures or anything else.
The 'Battle' is you against everything else. I have seen no sign of being able to have NPC allied ships under your control in a 'fleet' (so far).
The 'Explore' depends on how big you make the starting universe. However, it's only space travel. I don't believe there is any planet landing involved.
Early hours impressions: having a blast making ships! :D
Yet to actually leave the shipyard. WIll update as I play more~!
Update #1 (12/7/2014): I have left the shipyard and blown up my first space pirates. Hmmm, I think my ship's too strong.
Essential impression: This game is basically the developers providing you with the tools to start your adventure. How you want it to be will depend on you, it seems. For example, I made my ship too strong so wiped out enemies without feeling like I was in any danger. Unfortunately, it's impossible to assess what I can do to have a fun experience at this point. Work need to be done to give some cues to players to be able to intuitively assess how strong they are compared to enemies, etc.
There appears to be a lot more to this game, and I've barely begun to scratch the surface. Still would recommend at this point.
Update #1.5 (12/7/2014; later in the day): found strong enemies. Almost died. Fun fun. Seems the preparation a.k.a. building your ship is 95% of the fight. If I hadn't built my shape they way I had (out of pure dumb luck) I would've died. Me gusta...
Again, no real way to assess what can happen. You could say this is more realistic. :-P
Also, The missions just scroll and don't seem to be tracked per se. Not sure I'm a fan of this system. Seemed weak.
Seriously huge annoyance when you are trying to crawl within range of the station to dock in a big ship... Maybe I'm missing something? The Wark to within 10 doesn't always work... I often end up 50+ away when warping to a station.
There was an annoying ship builder issue that got fixed real fast, so really glad for the support. :-)
Not entirely stable on my machine for some reason, but this is the kind of game I am willing to play through a buggy experience and support (like the X games minus X Rebirth).