That's awesome on creating your first game! Congratulations 🥳
I did a quick recording of my gameplay in case it helps to watch someone play: Crabber by northcdev | Cap Recording
This is a great game scope for a 3 hour game jam, a simple concept executed well, and a great foundation you could expand on if you wanted to
I think some of the gaps I reckon I could have squeezed through, but was actually too big for 😆 Connecting some of the areas as 'no go zones' could help telegraph the player movement. I also think having the hitboxes slightly smaller than the player and the crabs could be a nice quality of life change, could still be just as challenging and fun with a little more forgiveness.
Overall this is impressive for your first game, and I hope to see you submit some more in the future.