Game type: Flash (I think)-based Side-scrolling, um... trajectory game? I'm not really sure what to call it. A skill-tester, maybe. Anyhow, you can also download it, if you like, to play when you like without having to connect to the web.
Time demand: Not much in theory, although you may end up putting a decent chunk of time into it trying to better your previous scores.
What it is: This is a game apparently based on the anime, and I'm sure that watching said anime would make things make a little more sense, but it's not necessary. I know this, because I'm honestly not even sure what anime it's based on, and have never seen it, and still got addicted to this Back In The Day.
The idea is to first hold and release your mouse button to cause a bike to crash into Some Guy at a given speed and trajectory. Said Guy then flies through the air, hitting or missing various characters on the ground below him as he bounces, and the idea of the game is to get as much distance as you can. Simple, right?
Well, there's a *little* added complexity. For one thing, you have a limited number of times you can crash into the guy again as he's airborne, and part of the strategy involves just when to hit him for the best effect. Also, as I mentioned, there are characters on the ground that he can hit, and each of these has a different effect. One will actually stop him on the spot, ending the flight. One slows him down, one changes the angle of his travel. Some give him boosts.
Once you hit a character, you then sometimes have a chance for a combo, which shows up to the right of the screen. This means that if you hit another certain character before any others (or sometimes before even hitting the ground), you get some sort of special effect, which often gives you a huge boost.
Even with the added bits it's still not extremely complex, but it is challenging, and addictive. Try it out!