Like many others I would have to say Marketing. It's far too easy to think a good game sells itself, but it's simply not true (just ask EA what their marketing budget is for Battlefield 3 and you'll get the idea). So I wish I knew it was worth spending time generating a forum-buzz weeks before release, and that offering a review site an exclusive preview build means they would be far more likely to play it and therefore feature it. Also, offering beta builds to respected active forum users to beta test the game would have been invaluable, not just from a Quality Assurance perspective but they might help generate more buzz on the forums. Being a one-man-studio I was just focused 100% on the final code+gameplay polish and like many others thought I would just worry about marketing after it comes out naively thinking, "how hard can it be?"
Nothing New My advice is pretty much the same as the rest of this thread. 1. Scope I think this is the biggest problem for most first-timers. It's really important to focus on what makes your game fun and unique. Everything else must have its value closely examined before being added to the first release. How to find out if a feature is critical? User testing! 2. Marketing / Visibility I still have no idea how to solve this. We've been trying to use Twitter / Facebook but it's too early to tell. We've also started emailing some bloggers. Someone told me that if your game is good, you don't need marketing (e.g. Tiny Wings), but the truth is, making a game that is obviously good is very hard. Most games fall somewhere in between obviously good and obviously bad, so how well you get your name out there becomes almost as big of a factor to your success as the game itself. Just my 2 cents . Good luck to my fellow indie game devs.
So far for me it's definitely been marketing. Wish I'd started marketing well before release day so I could get a big jump into the ranks... That and I wish I'd spent a little extra time and shelled out dough for better artwork. I now find myself with a struggling game in the store (though its only been a few days), trying to figure marketing out, and trying to give it a facelift at the same time... Oh and did I mention my masters thesis defense is in 3 weeks and I haven't finished writing it yet? ugh...
