I played the web version and it was fun. :) I liked the concept of the game. It's simple and catchy for casual gamers like me.
I would like to suggest some things though.
- On the Main Menu Scene, you could add some sound effects (like a "tick" SFX) when a button was clicked by the player so as to add some more life into the scene. Sound Effects add to the user experience.
- During my playthrough, I encountered some coins and stones but for some reason, when I approached them, they disappeared. Were they designed this way, or? Anyway, you could add some SFX and some particle effects when they instantly vanish to signal to the player that they're kinda magical items and that it's their design to pop off at some point.
- Nice terrain. You can improve the environment a bit more with some more assets. Maybe try this free asset pack my friend offers? https://www.assetstore.unity3d.com/en/#!/content/89939 It's fully free, don't worry. Plus, it's high quality.
- You can add a BGM (background music) in-game too and maybe transition it from time to time when the player goes from normal to panic situations. It can really put some drama and feel on your game.
You can find free SFX and BGMs on freesound.org and Machinima.com, by the way. I search those sites for great audio pieces myself and use their stuff on my own project.
Overall, the game has a lot of potential. I enjoyed playing it. Is it still in development?