Congrats on reaching water! There are lots of unlockables after reaching water for the first time. For example, you can unlock more turtles, and each turtle unlocks a special headgear once it reaches water. There is also a second part of the game that opens up after you craft the Signpost.
As for similar games, I actually made this because I could not find anything like it. I wanted a cozy digging game without monsters or time limits.