I am a bit sceptical about this startup.

Two friends interviewed there and both weren't impressed.

One of them is the best developer I know, with decades of cutting edge AAA games engine development experience, including in the MMO space and his words were: "they have no clue about games development and don't have much more than vapourware"

I hope he is wrong though and that the company is successful. They seem to be one of the few games related companies to compete with finance on compensation packages in London.