Full honesty the seagull startled me first time I died to it lmao.
Some suggestions and comments for this game if you're interested:
I definitely think this game is innovative. The shell system is done well, once you eat enough you can find a different shell and change, certain shells lets you block attacks and block the seagull.
The only problem though is how these features are communicated to the player. It took me a decent amount of time to realize I can avoid the seagull attack by hiding in my shell. I also think text telling your current health / max health along with the existing health bar would be nice.
The combat system is fun! It is a bit janky at times, but with the 3 days time I'd say its great. Especially the rolling, the rolling mechanic is very satisfying.
Good job!