Evil Genius Online, a free-to-play social spin off of the strategy classic, is now in open beta, with Rebellion issuing a hearty thanks to the series fans who helped shape the game during closed testing.

Rebellion described the reaction to the news of its plans to release a social Evil Genius game as “guarded”, but said the response from fans getting stuck into the spin-off’s closed beta was really helpful.

“I think it’s fair to say the Evil Genius community voiced some initial concerns about our direction, but it’s these same gamers that not only got behind the game, but played a big part in making it better,” Rebellion CEO Jason Kingsley said.

“They’ve had a really positive impact, without a doubt,” lead producer Steven Archer added.

“Our closed beta testers left no stone un-turned. It wasn’t just top-line features like the game’s balancing or suggesting new characters to introduce. We used a lot of subtle, but important feedback on everything from design, GUI – even down to the animations in specific objects.

“With such constructive feedback, the natural next step was to open the beta up to a lot more players. We’ve no idea how a new audience will react – many of them probably haven’t played the original Evil Genius PC game. We can’t wait to see what happens.”

Evil Genius Online will formally launch exclusively on Facebook in 2014. Head on over to Facebook to try it for yourself.