Is it possible to loose half of downloads in a few days?

Hi,

I have small game in store and have been slowly gaining position in keywords for several months. Got to first 10 in most of my important ones and aproximatelly 10 days ago I reached 200 daily downloads without any outside marketinig, just organic downloads. Game just reached 5000 downloads, about 2000 people still keep it installed. I reached around 3000 daily impressions and was quite satisfied.

But from that point everything started to slow down. daily downloads have been dropping in last 10 days and are now on 90 a day, impressions are also going down to 1500 a day. But keyword ranks are still the same. some of them even improoved a little.

I mean, of course there are good days and bad days, but 50% seems like too big drop. I just can not understand it.

Anyone have any ideas what may be happening?