I'm also stuck in the plant room, so I wasn't able to finish it.
The first thing I noticed was the awesome art. The game's concept is classic, and you put some great effort forth into that concept. I can see this becoming a popular indie game if you put more time in to polish it; some things that could use polish are the movement and controls (which are a little clunky), the arrangement of the art, and the overall flow of gameplay.
For example, having only two inventory spaces is kind of a drag, because it means you have to backtrack a lot. In the bottle minigame, I see what you were going for - the inventory restriction makes it more challenging, which is cool. But the other consequence of the small inventory is a lot of backtracking to rooms you've already been to, which is a bit of a drag. If you could find a way to make that backtracking more fun, you could make this game really awesome. For example, since you have a spooky theme going on, you could add some scares and/or random events to the rooms we're backtracking to. Given the positions of the required items, you probably have a good idea of how the player is going to move around in your game - use that knowledge to impress and entertain!
That aside, I hope you guys keep making stuff together. I have never been into point-and-click games, but I got pretty immersed in this.
Things I liked that you should expand upon: the art (expand upon it with better placement) and unique characters (expand upon it with more dialogue)
Things that could be better: the movement, gameplay flow, and unclear directions in the end