This is definitely simple and fun, and I really enjoyed it (even though my mouse is broken and I had to use my trackpad, it didn't feel that much more difficult which is a good thing.) For just a jam game, it's surprisingly deep in strategy - pushing rocks, lining up friendly fire, etc. More importantly, great job limiting what you wanted to do - I could easily see how you could get distracted making things customizable (speed, size of the flame, etc.) and lose track of the scope. Having said that, if you wanted to build that out in the future you have a solid foundation to keep going.
I wish there was some light music, although that's usually something a lot of games are missing. A parallax starfield would be cool but what you have works. Great job!