Let me start by saying that you very obviously know what you're doing, and there's not a lot positive that can be said that hasn't already rightfully been said by many others, this is a fantastic LDJam piece and I love the "A Short Hike" and "Night In The Woods" artistic DNA at play here - amazing work!
As you're looking to take this game further than the Ludum Dare, here's some feedback I hope might help you: - The camera sway is a bit too aggressive. I very rarely feel travel sick in games, but this immediately made me feel some discomfort - When working in monochrome it's important to develop your own visual language to separate interactive entities from the environment. I'd work on developing this language, as some objects for sure blended in. - Jump felt too floaty, I recommend increasing gravity past the peak - Acceleration on turn feels a little too long without much animation feedback to justify it, could probably be snappier? - As mentioned before, the boat can be a bit nightmarish - Dialogue is too segmented. Too many short sentences in a row that could feasibly be joint together to make the sentence flow feel cleaner and snappier. - You can definitely feel the pressure of the game jam in the writing, a lot of the dialogue feels rushed for the sake of content without much care for the grander narrative or individual character personalities. I think what you have as a base is absolutely perfect for a game jam, though you should consider rewriting chunks of it for a full release
**Please consider this to be full release feedback**, as this feedback on a game jam entry this would all be very nitpicky and you did amazing!