Rico's main objective is to hunt down and kill Tom Sheldon - his former boss, friend and mentor, now mental. But there's an awful lot on his to-do list to get through before that, such as - in the mission Johansson is demoing for us - rescuing an alcoholic informant called Karl Blaine. Having barricaded himself into the skywalk between two soaring casino towers, Blaine finds himself under attack from both sides with nothing but a bottle of gin for protection.
But here comes Rico to the rescue, swooping in using a stolen attack helicopter. He fires a hail of bullets into the glass panels of the skyway to create an opening, then attaches his grapple to the base of the copter and swings down to Blaine's side. Rico realises they're outnumbered so, flinging a few grenades as he goes for good measure, he grabs Blaine, leaps off the skyway and parachutes over the waterfall below.
Yes, the parachute is back, but it's been updated so it's more fun to control and easier to use for stunts. You can also use it in conjunction with the grappling hook to navigate quickly across terrain. Or you can choose from more than 100 vehicles in the game, including cars, trucks, boats, planes and helicopters. The next part of the mission we're seeing involves Blaine's car, which he's drunkenly run off into a ditch - so Rico uses the grapple and a handy nearby tractor to pull it back onto the road.
Blaine gets behind the wheel and advises Rico to go up top. "Nice Just Cause 2 logic - get up on my roof, you'll fight better from there," says Johansson with a smile. The car starts speeding along and Rico starts shooting away, as they're inevitably followed by a load of enemies in jeeps.
"You're completely free to move around and develop your own style and tactics for dealing with these pursuers," says Johansson. He blows the tyres out of one jeep to send it spinning and flipping across the tarmac, then leaps onto the other. Rico clings to the back of the vehicle, using the tailgate for cover and popping out to fire at enemies. With enough of them dispatched he leaps up, pops a bit of C4 on the roof, opens his parachute and sails clear before shooting at the explosives. The car blows up with a nice big boom.
Back on the roof of Blaine's vehicle, Johansson can't resist showing off that grapple once again. He attaches an enemy to the tailgate so he's dragged along as the car speeds down the road. Just for good measure Rico starts shooting him too, and the man splutters, screams and convulses for much longer than anyone in real life would.
But that's the whole point about Just Cause - no one's ever pretended this is the series to go for if you want a gritty, authentic simulation of real-world military combat. Just Cause is about big guns and silly stunts and cartoon kills and huge explosions. It's about cruising in a super-fast speedboat across a beautiful tropical sea, then zooming up a beach and off a ramp and parachuting into the azure sky, as the speedboat heads straight into a giant oil tank and explodes in a cloud of fire and thunder.
Avalanche hasn't lost sight of this, thankfully, and it's clear they're working hard to fix the problems with the first game. Just Cause 2 certainly looks prettier than its predecessor, and judging by the map it's bigger. But perhaps the key to making it better is really to focus on what this series is all about - and make it stupider. So far, so good.
Just Cause 2 is due out for PC, PS3 and Xbox 360 later this year.