Although I recommend it, I have to preface this by saying it's incredibly unfriendly towards new players, and I have no clue how I managed to keep playing when I first started.

To build anything, it requires a surface-level knowledge on a lot of things, and I can't think of a single other game that does that. For example, if you want to build a basic battle ship, you need to understand buoyancy so your ship doesn't sink, you need to know how much space you need for everything to fit inside, you need to understand weight distribution so your ship doesn't tilt and sink, you need to know how to build an engine, you need to know how to build a gun, how to build a gun that won't sink the ship when it turns, how much propulsion you need, ammo, general resources...
And that's just to make something that moves and can do damage. We're not even getting into what's viable. The game's gonna kick your ass, a lot.

The GUI sucks, controls are something you'll need to get used to, the campaign aspects are also something to get used to...

But once you gain that surface-level knowledge, you'll see how deep the game is. Learning what each thing does is a very small part of the game. Things interact with other things in beautiful ways. You don't just have a DPS and health stat for each craft, there's intricacies in making them and destroying them. Why use kinetic over EMP? Why go with lasers instead of guided missiles? These are surface-level questions, and the game gets so much deeper than that. There's a lot of categories of stuff and a lot of stuff in each category. You can make something viable in a thousand different ways, so I feel this is one of those rare games where "you can do anything" really means something.

The faction craft are beautiful and you can learn a lot from taking them apart and watching how they work. It's a unique experience reverse engineering an enemy craft and using what you learned against them.

You can go small or you can go huge, you can make submarines, hovercraft, jets, planes, ships, tanks, walkers, submarines that fly and shoot teleporting nuke drones... Really, you can make anything.

Although I recommend it, I have to preface this by saying it's incredibly unfriendly towards new players, and I have no clue how I managed to keep playing when I first started. To build anything, it requires a surface-level knowledge on a lot of things, and I can't think of a single other game that does that. For example, if you want to build a basic battle ship, you need to understand buoyancy so your ship doesn't sink, you need to know how much space you need for everything to fit inside, you need to understand weight distribution so your ship doesn't tilt and sink, you need to know how to build an engine, you need to know how to build a gun, how to build a gun that won't sink the ship when it turns, how much propulsion you need, ammo, general resources... And that's just to make something that moves and can do damage. We're not even getting into what's viable. The game's gonna kick your ass, a lot. The GUI sucks, controls are something you'll need to get used to, the campaign aspects are also something to get used to... But once you gain that surface-level knowledge, you'll see how deep the game is. Learning what each thing does is a very small part of the game. Things interact with other things in beautiful ways. You don't just have a DPS and health stat for each craft, there's intricacies in making them and destroying them. Why use kinetic over EMP? Why go with lasers instead of guided missiles? These are surface-level questions, and the game gets so much deeper than that. There's a lot of categories of stuff and a lot of stuff in each category. You can make something viable in a thousand different ways, so I feel this is one of those rare games where "you can do anything" really means something. The faction craft are beautiful and you can learn a lot from taking them apart and watching how they work. It's a unique experience reverse engineering an enemy craft and using what you learned against them. You can go small or you can go huge, you can make submarines, hovercraft, jets, planes, ships, tanks, walkers, submarines that fly and shoot teleporting nuke drones... Really, you can make anything.