Tip: When determining a time limit, remember that players won't be as familiar with the level as you are. If you normally complete the level with around 100s left on the timer, others might run out of time on their first try.
I like it, but there were a few difficulty spikes, and it seemed more like normal difficulty. Also, I couldn't find the key in the second level, but I found the key hole. I didn't finish the demo, but it's really good so far, I like it.