I see that you're a young game dev, and it's always great to go into stuff young. There are some things that I would've added/changed to the main mechanic:
1. Indicate what dot makes which door open.
2. Add some audio. Make it ALIVE. Trust me, even just prototyping it with audio is a thousand times better.
3. Add some animation to it. Makes it less static.
4. And lastly, always try to iterate on the game concept. Try to think outside the box.
Besides that, great work creating a game in under 3 days!