Darkstar64, despite being your first video that was good! I'll also admit you have a cool voice.
I guess there are two main approaches to gameplay videos: 'Let's Play', and 'Montage'.
A Let's Play is an almost raw one-take recording of a gaming session, taking the viewer on a railed adventure with you and your experiences. These are very long.
A 'Montage' is heavily edited and only shows the interesting/funny highlights of a much longer gaming session. Selection of detail is the key. Hence it can be any length, but only a portion of the original session.
They have different aims and I can't say one's better than the other. They just need to be executed well.
I'm a fan of the 'montage' type because I believe compacting a gaming session's length to maximize entertainment. I don't feel that there are always chunks of awkward or boring moments to cut out; I feel that an entire session is awkward and boring, save for a few chunks of actual entertainment. They make up the final video, in which every moment counts.
But it ultimately depends on the game, the number of players, the audience, etc. So many factors.
I don't think I'm in a position to give advice anyhow, but this is all just what I've gathered.
Here's a new Fistful of Doom video
The [video] tag is deprecated, please use the [media] tag
(The game session lasted over 2 hours. Most of it wasn't clip worthy.)
