There are many free games on Steam, but if you're looking to get the most out of your freebie, then check out this RPG with over 300 hours of content.
It's no secret Steam has a wide selection of free games to choose from, especially when you consider the games that are part of special discounts and events, or ones that get free demos or early access. And even when considering the free games you can keep forever that are available on Steam, very few of them can supply 300 hours of content.