(Sharecast News) - Video game developer Codemasters said first half revenue came in at £39.7m as digital sales as a proportion of revenue continue to increase.In a trading update, the company said digital sales represented 53% of total sales in the period, resulting in an improved gross margin of 88.5%.The group had net cash as at 30 September of £17m.As a result, Codemasters said it was confident that the results for the full year would be in line with its expectations.Codemasters has a portfolio of racing games and generates sales through both new releases as well as through its existing catalogue of titles.The results include the launches in the period of ONRUSH (released on 5 June 2018) and the annual instalment of the F1 franchise, F1 2018 (released on 24 August 2018), as well as the company's back catalogue of games.ONRUSH received good critical reviews, although it made a smaller revenue contribution than the other revenue streams in the period, the company said."Whilst the company will continue to support the game with new content, micro transactions, price promotions and access via subscription services to build brand awareness for the future, ONRUSH is not expected to make a meaningful financial contribution in the second half of the financial year.""Sales of F1 2018 have been strong across all platforms and F1 2018 is expected to make a material revenue contribution in the second half of the company's financial year, particularly via digital sales."Codemasters said it would launch F1 Mobile Racing, a free-to-play mobile game, in the second half of the financial year "which will be accessible to a wider audience and potentially provide new revenue streams for the future".