i really like the sound effects! the gameplay look is interesting in the fact that they combine resistances is fun and unique. i also should add that the tutorial does help but ill also say some more on it later. the art style is unique and i like the retro style.
onto criticism. i dont wanna be too harsh and i really apologize if i am, i liked the game for the most part dont get me wrong, i played it all the way through.
i feel like the biggest issue with it does lie somewhat in the fact that there's no progression. tower defenses oftentimes i feel should have some sort of progression in either difficulty or unlocking new mechanics or like a shop. its fine you didn't implement that but it did make the gameplay feel more dull by the end.
in my opinion the music doesn't necessarily suit the game very well, i usually wouldn't point that out but it feels like i am listening to an adventure game sound track and not a tower defense game. the music isnt bad though, i just don't feel its thematically appropriate imo. THIS IS AN OPINION THOUGH!!!
some of the resistances were hard to see to me, i think this could be solved by making the goblins a little bigger. (specifically the water one and all of them when they were mixed)
once you understood the resistances it was quite easy. i think this could be solved from my earlier solution of no progression but im gonna give more suggestions. you could add combos maybe (like having to equip 2 attacks at once or do them in succession), you could add more attacks you have to do and keep up with. etc etc, theres a lot of ways you can do this imo.
i like that you had a tutorial but i think embedding it more into the gameplay itself could've helped a lot.
i really hope that this doesnt come off wrong to you, i really did like your game! good job on your first game jam!