Earth is a penal colony, where all sorts of aliens, or mythological creatures to us humans, are sent to serve their prison sentences. Honestly, with all that advanced technology, whatever alien government out there would be better served finding a barren planet out there to transform into a prison. Maybe with actual prison facilities, life support systems, or whatever.
You're a parole officer for these alien-monsters, making decisions on whether these monsters had been on their best behavior and deserve to go, or whether they need to spend more time in the slammer. Honestly, with tons of delicious humans right around the corner in this 'prison', it seems like a recipe for trouble. Life in a penal colony is probably pretty boring after all. I would be surprised if they weren't thinking of ways to handle the monotony.
To nobody's surprise, some of these monstrous folks are out there causing trouble on Earth, so it's up to you to deal with them.
Minus the absurd premise, the story and writing is pretty entertaining. There was one decently interesting RO who works with you on missions.
I messed up a ton of checks during the game, and got my clearance decreased until it became negative. Still, I managed to beat all the checks for the final battle, turning my fortunes around and ending the game as a top agent.
It's a fun adventure if you're able to get over the premise. Seriously, what makes you think these alien-monster-prisoners won't be tempted to cause trouble?