Okay I can see this in the hands of several species from My sci-fi RPG world. When I look at something and go..Welllllll Now...That is perfect for ( insert character or critter) I have to smile.
The grip looks a bit uncomfortable for human hands, and a little crowded, not enough room for all five fingers, and no real secure grip for a human hand....BUT, It is a perfectly reasonable grip for an alien hand.
The lack of any definite sighting system would also make it a bit intimidating to shoot for the typical human, but in a sci-fi world having it linked directly to some sort of HUD, eyepiece, holographic, or helmet display, or even a laser pointer type aiming system turns the slight drawback into an interesting feature.
The curved shape of the lower section and fore section screams for a crescent or curved energy blade or force blade projection system. allowing it to be used as a melee weapon as well...okay maybe that's too many first person shooters talking but it does seem like a valid modification to add