It may not mean people are getting bored, could just mean that fewer new customers are showing interest. That 7% could mean either or. It could mean that existing customers are dropping off while new customers stay strong or it could mean that existing customers are staying put, while new customers aren't coming aboard.
Also, with any product, retail store, etc. it's impossible to keep seeing sales grow year over year at high rates. Eventually you peak out and will experience small increases or decreases year over year. I mean, it would be impossible to grow 25% every year because eventually you would reach a max customer base and people aren't going to buy two games.
If you look at comp sales or same store sales for retail chains, you will see this. They may grow fast at first, but once the mature, they kind of stay put with only a little movement from year to year (unless they do something to drastically change their business (price increases, new merch, etc.) but even then, you typically only see that spike for one year, because after that your anniversering your previous year which included the spike.