Yes, The Superdeep is no masterpiece but the rather low rating has something to do with the fact that this is a Russian movie (at least my guess). What we get is some nice story with a solid production and acting, and some fine visuals here and there spiced up with a little hunch of horror. Of course, we all know too well the ingredients the story of The Superdeep is cooked up: The Thing and Alien may be mentioned here.
There are some logical issues (why the members of the expedition don't wear the full protection suits and gears all the time in the hot zone for example just can be explained by a mystic of higher rank) but I know a lot of movies published by Hollywoods greatest companies, or Netflix, Marvel and whoever, that got far far bigger holes in the plot - and better ratings. Anyway, if you like this kind of movies The Superdeep will deliver a nice snack. Solid to good.