I think the most fun I've had has been the spaceship building. I've only done a bit of space combat, but the spaceship builder while not perfect (like the inability to rotate parts) I quite liked.
No, best you can do is flip a part so that the connector is on the other side. But if a part is meant to connect on a side connector, there's no way to attach it to a top connector or bottom connector. Parts cannot be rotated.
Nope, you can flip some parts. But you can't rotate them. So, for example some parts can only be attached to the sides and others to the top or bottom. (or sometimes just the bottom)
There's quite a few videos on youtube showing this now.
I have the Frontier module at the back and its blank ass is just sticking out with absolutely nothing to attach to it that wouldn't look like an eyesore or remove the shower. Like, just give me the ability to slap my fuel tank there or maybe a little radiator or something. There definitely need to be more options.
Still, I agree. While it has some shortcomings (like lacking descriptions & previews), the ship building and consequently being able to walk & fly around in and with your ship is amazing.