The old grain warehouse on Prince’s St in Dublin’s south city centre, an imposing cut-stone building modernised with a glass extension and dark, elegant entryways, could form part of the decor in a high-tech thriller videogame. Instead, its chic exposed brick offices are home to Digit Games, which occupies three floors of the space for a rent upwards of €271,000. The location is testament to the success of the company created by Richard Barnwell in 2012, and now Ireland’s largest game development company.  Following an acquisition last year, Digit continues to grow, despite not having access to the tax relief on…