Good job implementing the game systems for this being your first game jam! I think you did great with the pentagon tiling system and detecting valid spots to place things.
I don't usually play games like this, but it did feel like things moved slower than I wanted, especially since I can't come back to this later without leaving the application open.
One of the other biggest pain points I feel is the audio. I think it's great you can toggle it on or off, but when it's on it's very repetitive. The music loop is super short, so it gets old really quick. Also, not sure I'm fan of the sound effect when you place things, it's a little bit jarring. Something that can be done to help create more sound variety is to add some slight variation to the volume and pitch of the sound effect. It goes a long way to keep things from getting stale as quickly.
That said, you did do a good job. I think your game has a pretty unique interpretation of the theme. Overall, I like it.