even if we make assets from scratch? also as long as we dont sell it its ok right?
You still use otherones graphics, right?
No, copyright doesn't work that way. As long as the company hasn't stated - it's ok to use their stuff -, you'd have to ask. Which is the best way to go anyways.
Maybe most companies won't sue you, for taking their content, but that doesn't mean that it's allowed.
The reason I put no demakes / remakes in the rules is of copyright violation reasons. If you'd use your own game, it would be similar to using assets, I'd say. Because there is something already done, that you are building upon.
Next year I'll change the rules quite a bit, to make it even more specific.