Their reboot of Unreal Tournament failed. And so did their moba named Paragon. Arguably, their Fortnite Save the World also failed. Gears of War Judgement had poor sales for a Gears game though that may have been mostly developed by People Can Fly.

Generally if we ignore Fortnite and Infinite Blade(a mobile game), their last successful game was Gears 3, from 12 years ago. They basically only have Fortnite, Unreal Engine and the Epic store.