I don't have problems with my sound in other games nor multimedia content. Only in this game the audio stutters and is very annoying. Have anybody else experience this?

No, I don't have any idea about it because I don't face any problem.

We’re currently trying to find a work-around for this issue with ./play.it team, cf. this bug report.

Right now the only way I found to get correct sound quality is to have pulseaudio running prior to the game launch.

It works fine now after upgrading xubuntu :-)