Everplay shares rose 8% to 457p after an update showing its Wardogs game is selling faster than analysts had expected.
Wardogs has now passed 3 million copies, the milestone Panmure Liberum had pencilled in for the whole year.
The broker said it was the second milestone the game had smashed through, pointing to a rate of sale well ahead of its forecasts.
Selling 4 million copies does not look out of reach at this stage, according to Panmure Liberum.
The broker had argued on Friday that the shares were already pricing in an upgrade.
At that point it moved its revenue forecast £10 million ahead of the company's house brokers.
Hell Let Loose, the group's other big title, has sold 1 million copies, which Panmure Liberum estimates is split roughly evenly between console and PC.
That is in line with the broker's forecast of £20 million in revenue from the game this year.
It expects Hell Let Loose to sell at a much slower rate than Wardogs, making this very much a Wardogs story.
The shares trade on about 12 times enterprise value to operating profit, at the top of their historic range on a sales basis.
Panmure Liberum said that meant the valuation was increasingly full, but the momentum was with Everplay.
It added a caveat: the stronger this year's performance, the harder it becomes to grow next year.
Everplay will need continued operating momentum to sustain its valuation, according to the broker.
Panmure Liberum kept its 'buy' rating and 485p target price, around 6% above the current share price.
