I'm SentinelProxima on YouTube. Most of my videos are of the
Repton series of puzzle games, and I just give brief comments about my solutions in the video's infobox. (I don't like the sound of my voice, and I usually don't have enough to say to fill up a video.) However, for my
XOR walkthrough I did a spoken commentary on each level.
How much work -- not much, though it depends on how good your computer is (mine finds it difficult to process the game and the recording software simultaneously, so controlling the game becomes a little jerky and I need several more attempts than I normally would). Also depends, of course, on whether you're aiming to just complete the game or show a "perfect" solution. (My video walkthrough of a "perfect game" on
Iji stops midway through Sector 5 because it just became so tedious -- especially as I had already completed the challenge and had nothing to prove.)
Processing the video afterwards isn't too bad, but compressing it takes a while, so make sure you have something non-computer you can pass the time with. I recommend VirtualDub.
Yes, it's fun
Just don't go into it expecting to get huge numbers of views or comments.
