I would say that without the camera it has ps360 level of graphics(take into account that i don't like too dark games so i always put high brightness, the game should be darker than this)
(3 very creepy guys too intent on looking statics on a tv to care about me lol)
but the game is focused on the videocamera and with it the game looks better expecially with the night vision on(that seems to be central to the game, the night vision is mandatory if you want to look anything in the many dark spaces but it drains the battery fast so you always need to find batteries)
EDIT:
I tried Doom 2016 demo on the gpd win and well the gpd win didn't explode despite Doom on PC requires at minimum 8gb of ram and an hardware that's way more powerful than the one on the gpd win lol, the game was slower than it should be but it ran better than some other older heavy games, here my post:
http://www.neogaf.com/forum/showpost.php?p=251582222&postcount=2912
If the gpd win can somehow "run" Doom as is then i'm sure that with the right downgrades and optimizations Doom on Switch will be a great port