Shadowgrounds 2 is basically Alien Breed, only with better graphics. So it does nothing new, but what it does I find enjoyable, having rarely come across such games.
The story is pretty forgettable, but adds an extra layer to the game - a military base is attacked by a horde of aliens, and you seem to be the only person capable enough to do something about it.
It doesn't make much sense, but it adds to the experience.
There's also enough attention to detail to make walking around that base a tad creepy, and the music is just good enough to add to the entire experience.
It isn't scary, but it's the closest you'll get to it, considering you have a top-down view, and can see things coming from a distance.
But as fun as this game is, levels are short enough & enemy behavior is predictable enough for the game to become stale after a while.
Just kill horde after horde of enemies & move on.
There aren't that many types of enemies (many of them are unoriginal), so after a few levels you get to see them all.
And there aren't that many weapons you can use.
You are given more characters to play the more you advance, which are interesting, but by the time they're introduced you already invested so much time on the main character that they feel more like an unwanted distraction.
And by the end of the game you realize there's no purpose to them being there.
You can level them up & level up their weapons, but not in a unique way, so it feels more like a pointless distraction than a bonus.
The game also feels rushed - levels are short & sparse of interactable items, there's only one boss battle, and the plot you're trying to advance gets resolved suddenly & unexpectedly.
Playing the three characters, you're trying to get them to meet one another, but when that happens it's more of a surprise than a feeling of accomplishment.
The odd graphical glitch or slowdown doesn't help either, as well as the ugly character animations & bad unresponsive AI.
Also, Normal is almost too easy.