The shrinking boundaries of a battle royale map are normally just an inconvenience. You have plenty of warning before they shrink, and a generous stretch of time outside of the zone to make a last-minute dash to safety. Not so in Firestorm, which realises the boundary as a wall of fire you can see from almost anywhere on the enormous playing area. It shatters buildings as it moves. If you’re too close your vision starts to turn red and the air fills with ash and burning sparks. If the fire overtakes you, your vision whites out almost completely and you start sizzling to death.

Firestorm is Battlefield 5’s battle royale mode. Free to BF5 owners, it throws 64 players into a map ten times the size of Battlefield 5’s largest. Players dive out of planes at the start of the round in squads of four, and try to fight their way to the middle to become the last squad standing. The map is so big that the ring that determines the starting area doesn't cover the whole thing. Each game takes place in a slightly different portion. Developer Criterion hopes this will improve the mode's replayability by offering unpredictable drop options every game.

You basically have two choices when you drop from your plane onto a battle royale map. You can skirt the edges, hoover up mediocre loot, and try to survive, or go into hot zones right away to scrap for the best gear, and take that advantage into the final gun fights. The aggressive, roaring border of Firestorm’s map makes the safe approach much riskier. Several times my team and I found ourselves running at full pace away from the flames, taking pot shots at other fleeing teams either side of us. When things get really bad you might find yourself in desperate firefights behind the flame wall, firing wildly at enemies as the sound of roaring fire fills your ears.

Firestorm’s deadly border is one of a few elements that the devs hope will separate the mode from Apex Legends and Fortnite. A wide range of military vehicles (and a tractor) give players more ways to run each other over. Highlights include a small prototype chopper and an aquatic troop transport that lets you drive in and out of lakes. You can discover most of the vehicles parked near towns, but they are quite fragile. A few RPG blasts can take out a small tank, and the aquatic car and chopper have no protective carapace to shield passengers from headshots.

For the really good stuff you need to find a bunker. To open one, two team members have to twist two wheels either side of the entrance as a very loud alarm tells everyone exactly what you’re doing. If you make it inside without getting mugged you will find a proper tank and, if you’re lucky, a safe. When the community learns the location of each bunker you can expect these to be hotly contested at the start of each round.

It seems you can find a safe in any house, if you get lucky. One player has to spend a while cracking it, but it’ll spew out top tier loot. Rarer loot doesn’t mean a gun will do more damage per bullet, but the best guns have decent attachments and may have improved rate of fire.

Criterion says the guns behave exactly as they do in Battlefield 5 multiplayer. They haven’t messed with the weapon balance, but the addition of player armour will affect their killing power. The devs want players to survive longer than they already might in a BF5 multiplayer round, so they have added metal armour plates. You have to equip the plates by shoving them into your vest with a left-click, which can make for some tense moments as you try to repair your armour in the middle of a firefight.

The map itself is Firestorm’s most impressive asset. It’s vast, which means there is a fair bit of down-time as your team runs between places. On the plus side there’s a chance you can get caught in the open, and when multiple teams converge with long range weapons you get a more tentative fight than you might expect from Apex or Fortnite. Ammo can be scarce as well, so there’s incentive to make every shot count.

As well as open snowy plains, there are small towns made up of entirely destructible buildings, as I discovered when a tank crashed through the wall of a barn I was hiding in, collapsing half of the building as I fled through a side door. RPG blasts and air strikes (called down with flare guns you can find in any house) can shred a building and leave squads inside exposed. Air strikes, like the rest of the game, look and sound spectacular. There's in interesting mix of land and water, and a huge dam presents a big challenge for squads brave enough to risk getting stuck looting it.

After a few hours of play Firestorm feels like a successful attempt to adapt BF5’s vehicles and weapons to the battle royale format, though it falls in an awkward place in the wider battle royale genre. I love Battlefield’s rickety, temperamental guns: they feel heavy and deadly, and sound incredible. I wonder if that’s enough to tempt Apex Legends fans away from Respawn’s beautiful, snappy shooting, particularly when you have to pay. It’s a great treat for Battlefield 5 owners, however, and the huge, varied map will surely inspire the sort of war stories that Criterion wants players to tell.