Oh I love this kind of game, best training for eyes, especially for half-blind old guy like me
I found 40 and that one I marked as "40" is slightly unfair, because less than 70% of his graphic is visible... but OK.
I love how you hide No. 33 in my markings... Really clever and elegant.
Here are my findings, but I suggest that you try yourself, because it is really fun and point in this kind of games.