Now there's an objective I can get behind.
I like the aesthetic and the sound effects, but the gameplay is a little off. Think about the sort of playstyle you're trying to encourage in your players; the aim is to keep everyone alive, but it's a lot easier (and no less rewarding in terms of points) to just focus on whoever's nearest the cart. Once there's only one person left, you can keep going until you get bored, and the only challenge is in navigating between them and the cart.
Think about how you can incentivise your player to play properly; maybe have a score multiplier depending on how many people are still alive? And instead of having the game go on in perpetuity, have a time limit, say, "summer ends in three minutes" (sounds unrealistic? Try living in Britain). That way, players can meaningfully compare their scores, i.e.: "I got 5,000 points in three minutes".
All that being said, this is a really solid game for a first project.