The answer to the question here: there could be many reasons for this. The one that stands out is the fact that the market is very crowded and thus, to get traction in the early days, you need a lot of marketing. The method you have adopted (blogs, forums, videos, etc.) sound like a good start.
To make money — and since the app is free, I presume you are looking at ads — you will need traffic. That traffic isn't going to come in a month; it may not come at all. It seems you've had high expectations and are disappointed at not meeting them. So, yes, here are some of the things you did or are doing wrong:
* the market and the offer (as a combination, not separate) — A crowded market and a me-too offering. There has to be something distinct, something that makes you stand out in a market as crowded as this.
* the marketing itself — You need to be a lot more aggressive in marketing, get your app out on a lot more places. Even if a few blogs aren't publishing as quick as you'd like — and there's a reason for that — be persistent. With this kind of an app, it will be difficult. But not impossible. Get traffic in as many ways as you can.
In some ways, as far as the traffic is concerned, you are also limiting yourself. Why advertise on just game related forums? You can go anywhere you think there is a good percentage of Android users and post. Build some reputation and you will drive some traffic. Again, the key is to be persistent. You may not meet your expectations but the traffic will go up.
Great job on getting something out there! You have made some mistakes, and set some really high expectations, but you have something that you can learn from, if nothing else.