You guys are doing an excellent job!
I'm not sure if deleting the UI and sinking mechanic is a design decision but it makes the game much more relaxing and fun to play.
Although you should think about a gameplay loop, maybe some storytelling and puzzles. There could be more ways of interacting with the world apart from sinking lily pads, that way you could reconsider the level design and the objective of the game.
I'm not sure what the aim of the project is, but usually the objective of a game is to be fun. If that's not what you are trying to achieve then you can focus on what really matters to you and if it's a students project you should focus on making a game for your target audience (theacher, proffesor or whoever will play this).
Keep it up with the excelent job and remember i'm just some random guy from the internet, you don't need to take my advice if it's not convenient, but I love making suggestions.