Nice fun idea. I really liked it. It reminded me of the fun parts of Kerbal Space Program, but a lot easier which I really liked :)
I initially thought it was bugged because I thought I was supposed to drag from the inventory to place it on the assembly area rather than pressing to select the part and then pressing in the assembly area to place.
Also it would have been nice to have some sort of transition from when the fuel runs out rather than just an abrupt cut. Maybe like a result so we get some feedback.
I managed to find an exploit which allowed me to fly forever, which kind of broke the game a bit.
Good job with the game! :)