HelloOooOO,
I put in the video a few suggestions at the end, but honestly i don't think they're very good ideas hahaa.
Idea 1) Being able to hide under certain objects (I tried to hide under a starfish and I couldn't aAaAAAAaaa) I think it would be nice to have something like that, though maybe have a duration for how long you can be under there for. Either that or we have the option to bury ourselves? Afterall, turtles apparently do this anyway to hide form predators
Idea 2) Adding a few little rivers that go towards the sea. This may be able to give you an option to swim (maybe holding spacebar dives the turtle instead of jumping like on land, or just have them jump out the water a lil) Obviously you can have different mobs that are in the river that are hunting you too so that neither land or the river is safe. Alligators and river otters naturally hunt lil turtles, plus seagulls can technically dive into the water too. 'Pick your poison' kinda thing.
Idea 3) Different weather options. Instead of having animals or other creatures attack our little guy, having stuff like storms or wind blow them slightly further from the sea - which may also interfere with other creatures mind you - may be fun. However, I would understand if this is hard to code ;-;
Still, having to dodge a lightning bolt or need to sometimes take time to hide from the blistering sun would be interesting.
Regardless, I think you can tell I had a lot of fun playing the game. Please continue developing it, I think it's a very good game idea with incredible potential!!!