This game is looking really nice at the beginning. Some interesting character classes to choose from, each has its own mechanics and although at first it seems complicated to learn them, it's not that bad, just try them and the rest is learning by doing. There are however some things which could have been elaborated. How many crawlers do I need, do I need to recruit them? And so on. But it's easy to learn and the remaining questions may be answered by using a search engine of your choice.
Though mechanics are somewhat complex and interesting and yet the game can be played casually. There are not really any unforbidding choices, everything can be compensated sooner or later, which I also like. So You can have your fun!
So why the bad mark? Because apart from the main storyline, all dungeons are generic, randomly generated, the items also. You level up and so will the dungeons and items and monsters. But there is not really anything new or extraordinary interesting. If you played for example Baldurs Gate and found a +2 Sword, this has quite a value and you will be quite happy about this find. In StarCrawlers You will find many items with many properties constantly changing and it gets tedious to compare them. Making progress will become boring, because everything which is progressing is just the level of the monsters and items.
Of course You may just play the main storyline. Then the game will probably be quite hard and nevertheless not to interesting either, because in the end, most things are kind of generic, even though the dungeons and monsters change a bit.
I started the game and had some hours of fun, but then I lost interest. If You don't mind completing the game, then I definitly recommend buying it on sale. But don't buy it, if You like to have variation or a good story (the story is ok, but rather thin). There are some interesting choices to make (storywise), but since replayability value is low, unfortunatly most of them will never be discovered.