FEAR has always been a game of two halves, both heavily involving people being cut into halves. On one side, perhaps excepting Crysis, it's the most cinematically kinetic shooter on the PC; on the other, a story-led atmosphere-fest. It's equal parts Hong Kong gun opera and Japanese horror.
This (standalone) expansion pack rarely deviates from the - ahem - mandate, and this is both its strength and its weakness.
When it does deviate, it mostly just lifts tricks from its peers. For example, rather than playing the point-man of the first two parts, you play another FEAR team-member in the same area as the original, but with different objectives. This means we spend time in similar locales, getting different perspectives on What We Thought We Knew. Like Half-Life's Opposing Force and Blue Shift, basically.
Other changes - such as new weapons, new enemies and more AI team-mate company in parts - are a little predictable. There's certainly some eye-rolling when you play the opening. It's fun, sure, but all a little familiar.
Then you play some more and realise that Perseus Mandate is not just 'fun'. It's FUN. The AI remains excellent, everything explodes. The horror, at its best, is genuinely spooky. And the way people turn to red mist if you hit them right with the shotgun never gets stale. The new additions, while not exactly major, fit the game well: the grenade launcher just gives you more chances to see the game's explosions.
Your closeness to your team-mates leads to some oddly moving scenes. Even the more horror-styled monsters work well, with one in particular (we're edging round spoilers) giving you an actual reason to be nervous when approaching the ever-present blood smears.
A seven-mission campaign, Perseus Mandate isn't exactly large, but it doesn't outstay its welcome and there are three bonus missions unlocked when you complete it. FEAR's horror/action/slo-mo domain remains modern gaming's equivalent to the missing-in-action Max Payne. Fans won't be disappointed.
But despite being standalone, the pack is less easy to recommend to newcomers. The game does a spectacularly bad job of introducing you to its fiction, assuming that everyone knows about the ATV Corporation and why you may be shooting them, and who that spooky girl and bloodstained geezer are.
While you don't have to suffer extended cutscenes, the narrative is simply confusing. Also, outside of the vivid hallucinations, the environments are boxy and continue the concrete-with-everything scheme. There's also a little too much Halo-esque repetition of scenery.
But much like Halo, if you're looking at the environments that closely, you're missing the point. FEAR is about the action - either pillars and flesh exploding as a round collides with them, or the sudden, disturbing stab of light and sound in the horror sequences. And in those terms, Perseus Mandate does nothing to disgrace its lineage.
A container full of bloody FEAR jam