You'll remember Halo best for those massive sandbox levels where you were free to explore and fight however you pleased. The Halo in your head was filled with open ground and Warthog rides and battles on open fields beneath bright blue skies. Except it wasn't, was it? Think hard, now.
There are only three truly open maps in 343's pixel-perfect HD remake of Combat Evolved, same as it ever was. The game begins in narrow corridors aboard the Pillar of Autumn but immediately opens up on level two - Halo - where you'll race around some of the biggest spaces in the game and take on objectives in any order you please.
Truth and Reconciliation sends you back into narrow corridors for a tour around a Covenant ship before you're let loose in two massive open spaces - Silent Cartographer and Assault on the Control Room.
This is Halo the way you remember it - drive a vehicle or don't, stand and fight or run and hide, rescue your allies or leave them to die, attack from the left or the right, kill everyone or sneak on by. When Bungie made Halo 3 they made almost every space as wide as Assault's - though none as open as Cartographer - because it's those moments and choices that defined Halo and made it great.
Those moments haven't aged a day. Ten years after Halo first hit shelves and its sandbox combat has still never been done better. The biggest surprise when you play Combat Evolved again is just how well the sandbox still holds up. The AI enemies seek out useful cover, react intelligently to your more elaborate setups, and vary their offence as you vary yours.
Very little changed between Combat Evolved and Reach - enemies got a little smarter and spaces got a little wider, but the sandbox combat in this decade-old Halo still feels modern and different.
But there's a reason sandbox shooters are rare; why Halo 3, ODST, and Reach stand almost alone on 360, the half-good Crysis and Crysis 2 aside. Because making open sandbox levels is hard. And the rest of Combat Evolved is testament to this, built as it is upon the kind of ancient room/corridor shootery developers haven't tried to sell in years - and that's a problem when Halo Anniversary is sitting on shelves beside a decade's worth of progress.
Halo's weakest levels were weak pieces of design even back in 2001. Ten years on, they're antiques, and 343 have very deliberately done little to improve or fix anything that came before.
There's grass now, reflections, better water, new lighting and better particle effects. Somehow Halo Anniversary's HD mode looks exactly how Halo always looked in your head. The blanks you filled in with your own imagination have been patched up with perfect art design from the teams at 343 and Saber.
But it's the animations and lip synching, not the AI, that gives the game away. Still running in the old engine, those beautiful 2011 models expose every flaw in their 2001 animations.
Most HD remakes get a spit-shine that's on par with a remastered Hollywood classic, but Halo's makeover is more akin to the Star Wars Special Editions from the mid nineties. This is Halo the way it would have been if the original creators had the power and money to realise the Halo universe the way it existed in their heads, except in Halo's Special Edition, Han still shoots first.
Combat Evolved handles as it always did, running off the same classic engine with a second engine running on top to pump out the new visuals. The same trick jumps still work and the same AI glitches are still exploitable. The same rubbery physics power every explosion and the same handling makes the Warthog loose and floaty.