Actually like the idea of a main objective being under the mercy of a random roll. That said, I do wish there were more things that happened in-game that would change the flow of the game. Some easy examples you could explore could be having more enemies spawn as the timer drags on, enemy variants, and pickups that boost player.
Also, you should generally be careful about requiring players to repeatedly click mouse buttons. Not a lot of people have strong fingers and repeatedly clicking in a short period of time can be painful for them.
Overall, considering this is your first jam and you have a working game, congratulations are in order! Keep up the good work.
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Thanks for the feedback! I will try to make it that it continuously shoots when you hold the mouse button for other similar projects. Also when you have half your time left more enemies spawn. I forgot to test if my code for that actually worked though, maybe it wasn't a noticeable enough increment in enemies.