Indeed, that was it! God in heaven, I totally missed these buttons... but, as I'm quite embarassed to confess, I still don't know what to do against that french-accented bastard in the glowing forcefield-circle. I screamed at him with the megaphone but the guy still doesn't take me seriously... I'll try again this evening, but I'm thankful for every tiny hint. ;)
By the way: I really enjoy these games, I especially love voice and dialect of the hero. Absolutely hilarious! :D I hope there are more games in the pipeline. :)