Maltese publisher Insel Games has been banned from Steam for attempting to manipulate the review scores of its latest release, Wild Buster: Heroes of Titan.

In an email leaked to Reddit, the company's CEO appears to ask employees why they haven't purchased the game and left a review.

Although they don't specifically ask for a positive review, the chief exec seems to take issue with the fact that some members of staff have been reluctant to purchase the title and leave feedback.

In what looks like a thinly veiled threat, they add that anyone who doesn't buy Wild Buster will be asked to discuss their decision in person.

"I cannot force you to write a review (let alone tell you what to write) - but I should not have to. Neglecting the importance of reviews will ultimately cost jobs," reads the email.

"So I am asking you to do either of the following: buy the game and present me with the receipt until Friday night, for which you will be reimbursed within 24 hours, or explain to me tomorrow why you do not wish to do this. I would like to discuss this individually and privately with each of you."

After looking into the matter, Valve has decided to ban the company and pull all of its releases from the Steam store.

Anyone who's previously purchased an Insel title will still be able to gain access through their Steam library, but the publisher will no longer be able to ply its trade on the popular digital marketplace.

"We have investigated [the recent] claims, and have identified unacceptable behavior involving multiple Steam accounts controlled by the publisher of this game," reads a Steam update ."The publisher appears to have used multiple Steam accounts to post positive reviews for their own games.

"This is a clear violation of our review policy and something we take very seriously. For these reasons, we are ending our business relationship with Insel Games Ltd. and removing their games from our store."