Should do demo release or a different short game?

[g_michaelis]

Which is better? A demo release for the game I'm working now or do another game but a short one? Just for a first release. I've got everything I need but I'm still unsure whether to do either one of these. I can make another short game, my friend and I are thinking on it for the time being. I can do a demo too but

the character sprites were downloaded from a website and if I used them on the demo but the full game later on will use different sprites then isn't it going to look weird?

[TrickWithAKnife]

If it's a demo just for us, then place-holder art should be okay if you mention that's what it is.
If you are going to release the demo to the larger public, then it's probably better to get at least enough character art for the demo.