Tried this game out and it seems out; however, I have a suggestion. Add a confirmation box when spending fuel (I accidentaly pressed the "build instantly" button and lost 25 fuel)
the main problem with this game is that at higher levels you don't have much to do so people will lose interest, its like you get punished for playing it alot, with the long construction and travel times from raids you really dont have that much to do. still it was fun.