Magic
-considering it´s smaller game I would add only few spells
-player could pick them up by finding hidden magic shrines
-these shrines could be of secret character so player would have to explore to find them and get new spells
-every shrine could contain different spell
-spells should not be overpovered but either useless
-they should add more game solving possiblities(for example short invincibility shield to avoid dying)
-I think there is no need to make them upgradable(it helps balance)
Crafting
-I saw you can pick up some things like seashells/starfishes
-it would be cool if player could use them to craft things
-it could be done in more logical way for example stick+starfish+string=magic stick or stick+seashell+string=seashell mace or leather strap+wooden plank+starfish=starfish wooden buckler.... and many more of course
Puzzles
-this game is ideal for enviromental puzzles(sadly not sure if one guy can do that much)
-I would make few easier for story progress and few harder which would be explorable
-puzzles could be used to find some of those mentioned magic shrines
-I don´t know what are game posiblities in this case so can´t tell some exact ideas how could puzzles look
-few brainteasers would be awesome

bosses
-I always love some unique and hard enemies to face
