No Man's Sky, the highly anticipated space exploration game from indie developer Hello Games, topped the sales charts following its first week on the market. Based on limited preliminary figures, it's not doing quite as well in its second week.

GfK Chart-Track, which monitors the sale of media in the UK, reports that No Man's Sky has already given up pole position to F1 2016, a Formula 1 racing game from Codemasters. What's alarming is that, as VG247 points out, first week sales of F1 2016 are down 32 percent compared to last year's F1 2015 and while sales of No Man's Sky are down 81 percent compared to launch week.

But, there's a catch... a mighty big catch. GfK Chart-Track only tracks games sold at retail meaning digital copies aren't included. Translation - virtually none of No Man Sky's PC sales are taken into account here. It's also worth pointing out that No Man's Sky isn't available for the Xbox One, just the PlayStation 4 and PC, where as F1 2016 is offered across all three platforms.

Let's not glance over the missing PC sales as that's quite significant. No Man's Sky is currently the 17th most popular game on Steam. It's also worth noting that how long a game holds the top spot isn't exactly the best metric to determine success. Instead, many consider a title's staying power on the top 20 chart as a better indication of whether or not it's a winner.