I fired up TimeSplitters 2 for the first time in like two decades and immediately went 
at the aiming controls
Firing from the hip, there's no crosshair on the screen, which would be fine, but instead of a zoomed-in aiming mode or iron sights, aiming your gun roots you in place and gives you this light gun game-like pointer crosshair. Usually, aiming in an FPS game decreases your sensitivity to make it easier to make finer adjustments but this is the opposite. The crosshair is essentially a super sensitive mouse cursor that you control with a stubby little thumbstick, and it feels terrible to use.
Halo had been out for almost a year by the time TimeSplitters 2 came out so why didn't they just crib Bungie's homework 
I quickly went back and checked TimeSplitters: Future Perfect and sure enough, it just had a regular Halo-style crosshair as the default, called "fixed crosshair" in the options, with the old control style called "moving crosshair." I guess by 2005 Halo had established its control scheme as the de facto standard for console FPS controls
I'm sad that there's only a very narrow window of ages where people had the brain plasticity to master the controls and could really appreciate that game. If you're too young or too old, it's actually unplayable. For those lucky few, it was absolutely incredible. Split Screen GoldenEye in 1999 was just off the wall crazy fun.