Some people ASSERT that playing various video games has devastating effects on people, especially children and juveniles. Others consider it as aN invaluable way to educate people, so there is great debate among people about whether or not video games haVE a crucial role in people's learning.

Some people claim that playing several video games have devastating effects, specially in children and teenagers (juveniles sounds to me like teen prisoners), while others consider it as an invaluable tool for education, so there is a great debate about whether or not video games have a crucial role in people's learning. ---------- I've changed "people", because it appeared 4 times in a small paragraph, so I've rephrased a little.

I think that you have written a very good paragraph. I would, however, not use "proclaim." That sounds much too strong. How about something like: Some people say that playing video games has a devastating effect on people, especially juveniles, while others view it as an invaluable educational tool. There is, therefore, a great debate on how crucial a role it actually plays in learning.

The largest problem I see is that the sentence is too long. We call these "run on" sentences or "coma splices". http://en.wikipedia.org/wiki/Run-on_sentence I would write your sentence as such . .. Some people proclaim that playing various video games has devastating effects on people, especially in children and juveniles. Others consider them as an invaluable way to educate people. There is a great debate among people whether or not video games have a crucial role in people's learning.

there is a great debate go0d sentences I like the way you write these sentences >>>>>>>Good luck!!