A few bugs...
When you get hit by two bullets at the same time, two tanks spawn. It's probably because you coded the bullet to create a tank when it hits it.
Some bullets go right through the tank and some walls when they travel at an angle.
I'm probably going to come across as overwhelmingly negative when I say this but I want you to know that I have played way worse games in the jam and this isn't one of them. You had an interesting and simple concept involving dead tanks and bouncing bullets, and that fits the theme perfectly. However you only made two levels which means that you didn't really explore the mechanic to its fullest. I'm not sure what happened to you during development, but if I had to guess I would say that you just got bored, or maybe life got in the way. If the latter is true than you can ignore what I say next.
If I have any advice for you in the future, it's this: Make levels no matter how dumb they are, and fix them later. I know this technique works because I have been working on a game for eight years and I have to fight with boredom constantly to make it a reality.
I could give more constructive criticism on the art, visuals and sound but I'm not concerned about that. Gameplay comes first!
With that being said, I sincerely hope you improve as a developer in the future.