Such an energetic and lively OST! Definitely sounds like something I'd hear from a summer game. The last track also stood out to me because of it leaning towards a more atmospheric and calm feel and I like it a lot! That doesn't mean the other tracks aren't as good tho, I'm a huge fan of the beach feeling and I can definitely see myself playing a game using these tracks!
Overall just some pretty good and lively tracks with a bit of an atmospheric take on the end!
That's all I have to say really, have a great day :D
(P.S. was the third song inspired by Mario? I feel like I've heard a game with a similar melody and I'm just curious!)