Getting your story listed on the front page of a site like HN can't hurt!

Less flippantly though: this is a significant problem a lot of people ignore or sometimes simply don't believe. "If you build it they will come" doesn't work if "they" don't actually exist, or you don't get news to them that you have actually built it, or they can't see your's because of the tens or hundreds of similar (or at least not obviously dissimilar: your app might have a key feature the other don't but that is the same problem: getting that message to your audience) apps/games listed on the relevant store.

If you intend to sell something (these are moot points for many personal projects of course, as the audience initially might just be yourself for the sake of learning/practising):

1. Know your audience

2. Make sure your audience actually exists in appropriate scale and isn't already over-served by existing projects

3. Find a way of letting your potential audience know that you exist, preferably a non-spamy way

Points 1 and 2 at least need to be part of your design before you get far into coding otherwise you might spend time on something no one wants