Having played this game so many times (it is one of my faves) is there any weird and wonderful thing in IGI-2 you've done / found ? Here's mine ...
In the Ambush level after the bridge blowing up, i managed to get the APC to drive into the river ! Amazing it can run underwater - i even managed to blow it up in submerged on the river bank. You can also jump on the back of the APC in certain situations and go for a ride.
Also on the Ambush level - when the second chopper lands and deploys its soldiers, because its on a slope, you can jump into the belly of the copter ! It then takes off and you are whisked around the mountain side with a lovely view ... until you're informed that your way off target by IGI HQ and have to restart the level.
You can do Priboi's Villa level by following the road and coming in the back entrance - completely bypassing the front part of the level.
There's a guard in the Temple level in the second compound who stands outside the mobile - who is completely self-absorbed, and won't shoot at you no matter what - just wanders about like he's in another world, even when the alarm goes off.
In the Libya level, there's an invisible computer !. In the compound with 4 exits, containing the truck you have to blow up, follow the east wall along the inside (going north) till you reach the midpoint opening ... near there the computer terminal icon flashes up and you can access a computer which is not there ! Not sure what it does though ....
If you wanna get down a steep slope, switch to crawl mode - you can descend anything with no damage.
If you have the thermal imager on and you switch to the map view, you can sometimes see the enemy through the floor / roof of buildings
If you're in crawl mode and you fall into water (not shallow), you will be able to see underwater !