Lots of good advice here. However, something to keep in mind is the target audience, and your own purpose. If you are planning for a commercial project, then you obviously need a lot more attention and care, and more likely a team to help you. However, if this is your hobby, then don't stress over the small things, have fun, and realize that the majority of your audience will also be amateur game developers.
That's not to say you shouldn't stive to do your best even for freeware. There are some people that have the qualifications of making a commercial-like game for free, and that's all great and dandy. I've played a few myself, and I've played plenty that were below commercial standards. That's because I like playing games, regardless if they are commercial or not.
Have fun, realize your own limitations, and work with what you have.
Sailerius makes a good point: While a good game can always be polished, polish does not make a good game.
So.... create a good concept, make sure it plays well, has a good story that's written well, balanced well without being too easy or difficult, and is error free. Get it completed. Then, when you learn more skills, go back and rework some of the scenes to your advantage. Just because the game is complete doesn't mean you can't go back and apply your new skills later on.