For example, the second slide of the game shows "(Where.." then transitions to "(Where..where am I)" upon pressing Enter. I can see that there is an auto-transition that shows the full slide/sentence after about a half second, but that mechanic can be quite annoying for people who are just starting to press Enter because they've quickly read the "(Where..", and then suddenly find they have to click Back because they missed the rest of the text that unexpectedly appeared.
I get that you are trying to solidly establish the disorientation of your character, but if you just showed the full thought of "(Where..where am I?)" all at once, this is already being accomplished in the mind of the reader through the ellipses and short, repeated words/thoughts, plus the content of the sentence. The additional forced transition through a gameplay/interface mechanism actually takes away from that particular reader immersion IMO. Kind of like you're trying too hard to drive a message home, when it's actually better to just do less and trust the reader.
Hope that helps you out! What you are doing looks quite promising and has some novel/interesting ideas that nicely set it apart from other VNs. Definitely worth keeping an eye on.
Oh, and I just noticed that the "(Did his dick just got bigger?)" line should read "(Did his dick just
get bigger)". How's that for a strange grammar correction?