Developed by Bossa Studios, which is owned by the parent firm of Merlin production company Shine TV, it will let gamers team up to complete quests and fight evil.
Imre Jele, Bossa co-founder and creator-in-chief, said:
When creating our latest adventure, we wanted to capture as much detail from the world of Camelot as possible and give players a truly immersive and co-operative experience. It's certainly been a lot of fun so far.
We’re absolutely thrilled at how it's all coming together and cannot wait for you guys to be able to fight the dark forces of Camelot shoulder-to-shoulder.
A closed-beta trial of the game will be launched at Comic-Con International next month. In the meantime, people can sign up for it here. Merlin The Game will be launched publicly in the autumn when the show returns to UK screens for its fifth series, comprising 13 episodes.