Good job on the game, felt pretty nice while playing. But since this a post jam I'll try to be as critical as possible with my feedback.
Art. Despite the fact that its pretty cute, it lacks something. First of all, Fungus shouldn't be green. That could be count as an artistic choice, but real problem is that it has exact same color as the background. It kinda blends. Then, there is total abscence of background. I think this kind of game should have one. Also animations, I'll also cover this in gameplay section, since it relates with the enjoyment of the game, but yeah, game feel a bit static.
Gameplay is pretty fun, kinda reminded me of a fruit ninja, same kind of clicker. But there are major problems with that comparisson.
Firstly, Fruit ninja's whole selling poitn was juicyness, you feel satisfaction when you get that clean cut of many fruits. You can easily add that satisfacton here too. Maybe by adding some mechanics, like capturing multiple flies at once, or by adding more animations and sfx.
Secondly, mechanics. For now there is nothing to a game, except for just simple clicking around. You basically just have to aim good to get the score. Yes, you have a little progression here, when flies become a bit faster and spawn more frequiently, but there should be more to it. Maybe some kind of bombs, that blow up green flies, maybe some buff-fruits that let you eat even protected things, or maybe some kind of slowmotion effect. There are a lot of things that could be added here)
Overall, for now its too "jam" game. For it to be considered something more, you should definitely add more things. But given enough time its very doable. Good luck!