Thank you! I'm glad you liked it!
If you'd like the game to be longer it's actually very easy to build more levels, I didn't do more because I didn't want it to be too repetitive.
EDIT: give me a few minutes to craft some and I'll edit this message again with a version with more levels!
Here you go, the compiled game with 7 additional levels. I haven't play-tested them too much but I'm sure they are fine. The 14th and last level is generated randomly!
To get the game working, simply unpack the .zip and open the .html file with any browser, it should work.