Frontier Developments may not have formally announced a sequel to its delightful zoo sim, Planet Zoo, but that hasn't stopped someone trimming up the game's YouTube channel with some not-so-subtle hints that Planet Zoo 2 is on the way.

As spotted by our friends over at Eurogamer, if you head over to the series' official YouTube page, you'll find both the head and the avatar image has been updated with a '2' on the end.

This isn't a clue as much as full confirmation, even though there's been no firm announcement... yet.

It's not entirely a surprise, of course; Frontier did tease that a follow-up game was in the works when it released a trailer celebrating the sim's sixth anniversary at the end of last year. However, it's our closest clue yet that a game isn't just in development, but could shortly be out… maybe we'll find out more as we move into Summer Games Fest?

We thought Planet Zoo was a "wildly satisfying park-builder with a menagerie of lovely looking animals."

Vikki Blake is a reporter for IGN, as well as a critic, columnist, and consultant with 15+ years experience working with some of the world's biggest gaming sites and publications. She's also a Guardian, Spartan, Silent Hillian, Legend, and perpetually High Chaos. Find her at BlueSky.