In the 1980's, arcades were the biggest thing going for adolescents. Titles like Donkey Kong and Super Mario Brothers swallowed quarter after quarter from kids willingly trying to reach that next level. The arcades of the 80's have lost their luster due to the fact that games considered to be just as high quality have found their way online. These free online websites often have 100's of flash games ranging from puzzles, to adventure, to strategy. They are just as fun and addicting as the twenty five cent arcade games of the 80's, but are completely free.
Flash games are often made by independent developers with little to no budget, but can give player the same experience as the games in the classic arcades. They can be very simple or very complicated. Usually this type of game is something you can get into at the end of your lunch break, or in between classes. Flash games will not ever replace high budget console games like Halo, but they have their purpose. They are created to provide a quick game experience without much back story or barrier to entry.
These are almost always free to play, so developers earn money from them by displaying advertising in the game or on the site. This is a completely new way to support a quality game. There is no need to get change for a dollar when you run out of lives, because the in game ads pay for the development of the arcade game. The ads can change the experience, but free is always better.
Casual online titles have recently become a huge business with companies like Zynga creating huge hits like FarmVille and Mafia Wars. While most larger game developers ignored this casual game market, the ones that jumped on it first have now turned into multi-million dollar companies. Now with features like the Xbox live arcade, these simple, but very entertaining games are available in everyone's living room.
If you want to play games that make you think a little bit and are looking for strategy games or free online puzzles , there are a lot of different sites you can choose from. If you type a specific genre of game into Google, you will most likely get 1000's of results that are specifically tailor to that niche of gaming. These casual games are usually very easy to get into and do not take high levels of concentration to play.