Ok i activated my developer skills and these are my conclusions:
The fundamental problem of the game with the introduction of the 1.04 patch seems to be the totally messed up saving ability. The 1.05 patch does not seem to fix this problem (i'm using the eu version, but the situation seems similar with the na version).
The game does not save progress anymore, even restarting a checkpoint is not possibile. If you select restart checkpoint the game will bring you back to the beginning of the chapter because it is incapable of saving progress.
Without saving progress the game is incapable to recognize when a player has completed the first run and therefore will never unlock the extra modes.
Right now for a new player the new trophies are 100% impossible to obtain and i suspect that even the platinum itself is getting screw by the absence of right saving progress.
So why two players achieved this damned trophy? This is my hypothesis:
The game right now is incapable of saving progress, but if you have a past save file the game will recognize it and unlock the new modes.
As far as i can tell if in your past save file you already did the 35 min speedrun, the game will bug and you'll be stucked with the infamous 0/7 counter and the trophy will be unobtainable for you.
If in your past save file you didn't do the 35 min speedrun, the game will not bug and you'll be free to complete the challange mode and obtain the trophy.
How can we verify this theory?
@Banton_Grievous and @wuwiwa must follow what i write a few comments above (deleting the save file, reinstalling the game, doing a new first run). (thanks guys btw, luckily the game is very short and it shouldn't take you too much time)
If they will experience the same bug that we're experiencing, being incapable of completing a first run to unlock the challenge mode, the theory will work.
If they will not experience the same bug that we're experiencing and they will still manage to complete a new challenge run on a fresh save file, the theory will not work and we will have the confirmation that they are the chosen ones and we must accept our inferiority.
I quote @ToAzalea too, you said to have written an email to the devs, could you do it again with this infos? Thanks
These are my conclusions, let me now what you think. (also my english is trash sorry about that).