I finished my first HTML5 Game which was very modest in scope. I wanted to build a simple connect the pipes via rotation game.
It took me to 2 weeks to complete at 2-4 hours a day on my off hours, in total 38 hours.
I build it using Phaser, CoffeeScript and Sinatra. It uses LZ and store.js for storing data.
The hardest part was drawing the flow graphic overtop of the pipes as I had to reverse the animation depending one which way it flowed into the pipe.
If anyone is interested, I am considering open-sourcing the game. http://www.kongregate.com/games/omenking/piepezania