Nice! I like the automatic adaption of tiles, this may add a lot of user-friendlyness 
I have already seen a few games of this kind, and something they all have in common, is that the resulting spacecrafts look very blocky and flat. Even if you are limited to tiles, this isn't a strict consequence. One possibility would be to add a shadow/relief over the whole ship, such that it looks more 3-dimensional. And the engines are way too big, it looks quite strange to have them in every direction. Instead, you could embed small maneuver thrusters at the sides.
Another idea is to make the maneuverability of the spacecraft dependent on its mass and moment of inertia. Like this, a physically realistic simulation is possible, and another strategic element when building spacecrafts emerges.
Hello, thanks for your feedback.
Regarding the flat look, i have plans to create a shader to give a regular shading effect which will provide the
ships a higher grade of relief. Unfortunately, i don't know yet how to program shaders. Nonetheless, it's just a matter of time. Maybe someone will come up with a better idea to get this effect.
Regarding the engines' size. That engine is the first one we've made, and indeed it's huge like you said (though there'll be bigger ones). The idea to make a series of engines sorted from the cheapest and less powerful to the most expensive and powerful starting with the thrusters. When we get this done, people will think twice before attaching the biggest and most expensive engine to the sides.
Finally and concerning the simulation. The game physics control the ship's mass as you suggested. First I establish a density which BOX2D distributes uniformly in the ships surface. In the near future, when we have to manage with different floors, we'll modify this, since the conditions will be different.
Best regards.
