If you use MH as a pipeline to create your art assets, then there is no problem at all.
What you create with MH is licensed CC0, so you can use it anywhere you want (starting from version Alpha 7). And of course you can re-license the art that comes with your game to protect it.
You don't have to credit us, but it would be cool if you would make a reference to makehuman in your game credits.
![Wink ;)](./images/smilies/icon_e_wink.gif)
The MH code and internal data is under an open source license, so if you want to integrate MH in your game, for example as an in-game character creator, then you have to release the source code of your game as well.
And if you use MakeHuman to create something great, we would love it if you post the result here, as we are always interested in what MH is used for (plus it will get you some free advertising
![Very Happy :D](./images/smilies/icon_e_biggrin.gif)
).