Wow, really cool idea! I agree with previous comments, that I would've found it better to have the countdown timer integrated to the UI - personally I would even feel, that this would help your intention to create more stress, because I would always try to gather as much resources as possible now and come back at the last possible second. Now I'd rather return early and safely, since there is no penalty for that. I was also surprised to see that upgrades don't carry over the levels. All in all I feel this is a very unique and cool idea, which could be elevated by a few tweaks in game- and leveldesign. Great work, especially considering 48 hrs. Congrats! :)