It's what dkh says, the difference is a lot, in that I find the ship unbelievably cool looking, but the bar (even after revised) looks way WAAAAAY different, like they were done by 2 different artists.. I would almost say you just downloaded or ripped the ship background from some place, which if correct, you need to be sure you've got permission to use it.. if so, just replace it with your own creation, even if it doesn't look as good, at least you'll get the same style..
But as you said yourself, first concentrate on making sure you've got the adventure up and running story/puzzle wise, and later on when you're all 'finished', check for backgrounds/characters which might need to be redone to get the overal look the same.. remember, if the artwork differs too much between scenes, it will distract from the actual game itself.
Now some comment on the revised bar: the left wall looks too messy to me, maybe try to use the backwall and 'skew' it (don't know if it's possible with the program you use, but I know it was possible back in the day I used deluxe paint, I could take a piece and manipulate it in 3D, it seems my current program paint shop pro 5 isn't capable of that).. The tables could also use some extra color for giving the legs some extra dimension..
If you have trouble creating your backgrounds from scratch, just take a look (take a lot of screenshots) at other commercial games like 'monkey island' to see how they do it, and also use these forums, there are special threads on how to create backgrounds etc, and let other people help you get better and better, because you don't have to reinvent the wheel..
Keep up the great work.. we're just here to help you to better yourself and that also means giving some 'harsh' comments from time to time, but also praise

so don't let any of these comments get you down..