First, good job on finishing your game! I love the art style — it feels really polished. It’s minimalist but has great visual cohesion, and it fits the theme perfectly. After a certain amount of time, you could start to mess with the bottom masks or switch them up to make it a bit more challenging. You could also add some background elements to give the feeling that you’re reaching the surface — for example, the background could gradually become lighter as you get closer. Overall, great game!