So, the following is the list of games that could have been implemented with flash, however, they weren't. Some of the examples such as Browser Pong, Twitch and puzzle are really worthwhile to check it out because they are really amazing. Enjoy. :)
Browser Pong is a traditional Pong game played not in a browser window, but *with* browser windows. I think this one is pretty cool. Have you ever think of player ping pong game using your web browser windows? You have to check this out.
TWITCH is a series of minimal games within small Chrome windows. How fast can you solve them all? Each game only responds to clicking; mouse position and keyboard are ignored. This is the first game that caught my attention. It uses new window for different levels. Seriously, I have no ideas how it works. Great stuff!
Open new windows. Throw a beach ball through them. If I tell you it's less lame than it sounds, will you give it a shot? I saw this last year and it amazes me. A beach ball that roll over different browser windows and the gravity simulation are great.
Video & Picture Puzzle
A small experiment in generating puzzles using multiple browser windows and images or Flash-driven video. It confuses me at first, so basically, your puzzles are made of browser windows again. I won't spoil it though, you have to try it yourself.
Apophis 2029 is a Missile Command - meets - Space Invaders sort of game. Your job is to shoot meteorites out of the sky before they destroy you. I think the animation for this game is great. It works better with chrome though.
Arkanoid/Breakout type game. I'm sure you've played this kind of game before, but this come with extra, you have a power meter to determine how hard you'll hit the ball.
Real world racer
A Google Maps Racing Game - to maximum enjoyment, make "bvvv, bvvvvv" noises as you accelerate and "EEEEE" noises as you turn. A game that uses google map. You get to choose the race track. I never finished a race, I tried shortcut by driving the car directly to the finish line. ha, it didn't work! Computers won, Nil for me.
JS WARS is a classic shoot em up written to demonstrate the power of modern web browsers.
Berts Breakdown is an attempt to make a platform game using the new HTML5 canvas element. The graphic is really nicely done and it kinda smooth as well. It just like a game made with flash. By the way, it works better with Googl Chrome.