Thanks for the comment!
Yep, I actually had a fuel limit implemented previously, but it makes the game a little bit too hard. I might add it as an optional difficulty setting. For new players, running out of fuel gets very frustrating, and it's not a full sim like Kerbal where you can plan your delta-V requirements ahead of time. I'm not 100% decided though and I definitely need to play test it more and see how it goes...