Both Germax and gerhard_s add the scores of the separate minigames. Other similar games are scored by number of completed minigames so I guess the special rules should be updated and the scores changed to:
We need a good scoring for this one ;
I propose :
task cleared = 100 + score
task failed = score only
(why ? nb of tasks cleared is most important to my eyes, using only scores would be idiot : some tasks are complete with score =3 , others are complete with score = 26 (alphabet))