UPDATE 1-Nintendo's Mario mobile game suffers launch day server overload

Sam Nussey

* Users complaining of being unable to access game

* Nintendo says situation is improving

* Company has been slow to expand into mobile games (Adds company comment)

TOKYO, Sept 25 (Reuters) - Nintendo Co Ltd's hotly awaited mobile title Mario Kart Tour launched on Wednesday with many users complaining server overload meant they were unable to play the game - seen as a major test of the Kyoto-based company's mobile ambitions.

"The servers are experiencing heavy traffic. Your log-in request will be processed in the order it was received," reads a message that appears when the game is launched.

A Nintendo spokesman said the company is aware that due to heavy traffic some users were having trouble accessing the game, but that the situation is improving.

Nintendo has been slow to expand into mobile gaming, choosing to focus on its hybrid Switch console. Its online subscription gaming business has lagged rivals Sony Corp and Microsoft Corp. (Reporting by Sam Nussey; Editing by Jason Neely and Muralikumar Anantharaman)