I can not deny it is not easy to get all the sparkles on such a big map. Do you think I should change some of the timers so that the sparkles appear more often?
To answer your extra question: those two chests are decoys whose sole purpose is to distract you from the strength sphere. The strength sphere is actually not far away from this room, hidden behind a secret passage (it is not particularly well hidden; a hint: look at the ground). Opening one of those two treacherous chests will seal that secret passage (and the sphere) forever. Nothing prevent you from looting them after you got the sphere, though.
I attempted to click the wall that was behind the what i can assume was bat guano on the ground, but it didnt open even before i grabbed the chests if i remember correctly, am i supposed to use a spell or item of some kind?
-And to answer your question about the sparkles, you could maybe extend it to last for about 2 seconds, and then disappear for about 3-4 seconds maybe.