hm I feel like I didnt collect some crystals placed behind those pattern shaped walls, maybe I am wrong.
Maybe i'll just replay it again, wasnt that long anyways :-)
To clarify the small crystals are only used to unlock the gates and you don't need more than 4 to complete the game.
But as long as you are enjoying the game that is all that makes me happy. Do let me know if the end of game freeze still happens, remember to redownload the latest version in case you haven't already.