Hey agwoodliffe, thanks for the feedback :)
You're correct, most of the sound effects are from freesound. The scream letting you know you've been spotted is particularly blood-curdling I think!
It's an interesting idea starting during the day and slowly revealing the creatures to the player. The main reason I avoided this was I wanted to drop the player straight into the game and getting scared as soon as possible! However, one of the big problems I've noticed is how difficult to navigate the island can be. Allowing the player to first orientate themselves during daylight would certainly help.
Thanks again :)