Hi Stephane,
Are you creating your question directly in the Moodle Quiz module? Maybe someone has a better suggestion, but I was thinking you could consider using a Cloze question to achieve what you are looking to do. This would allow you to have three separate answer boxes in one question, so you don't have to worry about commas or conjunction phrases as parts of your answer. You'd still have to consider what order the kids would use for their answers, but if you have all three words as correct options for each blank, the code might look something like this:
"1. Found 3 games adventure in this sentance?"
{1:SHORTANSWER:=zelda ~=pariodus ~=mario}, {1:SHORTANSWER:=zelda ~=pariodus ~=mario} or {1:SHORTANSWER:=zelda ~=pariodus ~=mario}
...and the quiz would look like this:
