A fun game! I made it to Level 11 with a score of 142. At the beginning of the jam i came up with another idea but also with sheeps ^^ The game is fun to play and the difficulty does not spike up too quickly.
I would love some more feedback when you eat a sheep like a little effect to give the player a more rewarding experience (which was already mentioned). You did this already with the spawn of a sheep which is nice. It helps noticing that there is a new sheep especially if you reach a higher level.
What I noticed is that you can get stuck in the options menu when you press Enter on a volume slider. Or at least I wasn't able to recover any focus on the button at the bottom of the menu.
Overall a nice experience.