Very ambitious project, maybe even TOO ambitious! Spoilers for this review- I'll be using the word "uneven" a lot!
Starting with audio. You obviously took care for the audio to be detailed. There are NOT many jam games where sounds of the footsteps vary depending on what you are walking on. From the other hand- the pistol sounds like it had a silencer on, and you cant' hear the enemy shots, unless they are really close.
Graphics are pretty much the same. The cats look cute and the scale of the game is impressive. Blocky guns are ok I guess, but the enemies don't look great.
Gameplay. The guns are VERY accurate, but it worked for me- I just landed my shots from far away :) But I couldn't finish the game, because I couldn't slide under the thing in the quarry.
One of the most important skills in a game jam is time management. You need to know how much you can do in ten days. I'd say, that a game quarter the size of your would be impressive in a game jam. My general rule is to make the game in half the time and then have time for polish and bug fixing.
My advice- check out unity asset store for some assets, or work with an artist (I do!). Check out freesound.org for some good sounding sound effects. Focus on your strengths and don't overscope. I'm looking forward for your next game!