Space Crash Backstory

Space Crash on Tartarus V
A ship carrying a valuable and top secret cargo of organisms(some of commercial value some military) has mysteriously crashed on a mysterious and inhospitable planet (notorious for shipwrecks).  The corporation has dispatched a cleanup squad to recover  the organisms and destroy  the evidence of those they cannot recapture,  however the crash has also created attention amongst mercenaries hoping to capitalise on the misfortune and  recover some of the creatures, and parts of the ship  for themselves( and the shadowy powers employing them).
The planet is not without life however, and although parts of the surface are covered in thick ice there is a giant network of deep canyons created by thermal activity full of alien organisms.  One of the lifeforms  is a type of control creature- a brain creature that is largely immobile but utilises and controls other to feed or protect it. It is one of these creatures- grown freakishly large that has  caused the crash of the passing ship and the scattering of its cargo. (The concentration of life forms on the ship attracted its attention, and it directed the occupants to land/crash the ship on the planet).
A desperate struggle for survival is created for the inhabitants of the planet, the surviving cargo of organisms and competing factions desperate for their recovery. (For the landing parties time is essential  for while the control creature remains the longer they stay the greater the possibility that they too might fall under its control.)
Ideas and Notes:-
When brain creatures are killed their attendant creatures are released.
Brain creature itself is of military interest for remote control/teleprescence, and these organisms are of interest/value to the corporation.
Control creature has learnt/evolved to control native creatures, and has learnt to control some human and alien races through contact with previous shipwreck survivors- possibility of survivors of the crash might mean an opportunity to learn more for it to be more effective in its control.

Hybridised or genetically modified humans or creatures are effectively safe from control in the short term.  The corporation and the mercenaries may be aware of this and maybe have sent modified humans/races on their recovery missions(Mercenaries could be halfbreeds- corporation could be more gene modification/surgical) .
Control creature does not acquire peoples memories or identity into its own  but hijack and puppeteers them . Control creatures are not a hive mind as such but  compete with each other.
Control creatures have a limit to their control capacity and their ability to divide their attention amongst many subject at once-(in their habitat they are susceptible to massed attacks by swarming creature ). For this reason it is best that coordinated approaches in number or small teams will reduce the ability of the creatures to take command of corporation or mercenary operatives.
Because control creature rely on a line of sight to their victims or servants- they tend to live at the intersections of the giant  canyons.
It is believed the  crash site is located near site of an ancient meteorite strike, where the control creature responsible is believe to exist.
Characters or creatures to work on from the world.
Corporation recovery/cleanup team characters/(or creatures).
Mercenary team/(or creatures).

Cargo creatures to be recovered.
Native creatures fauna and flora of the planet.
Brain/control creatures.
Shipwrecked survivors marooned on the planet.