The singleplayer campaign cast you as a sort of land-Pirate, a freelance tank commander wandering the battlefields of a post-apocalyptic Earth ruled by Mega Corps in search of useful loot and supplies. Your enemies are the Mooks of Tyrakian Global, one such MegaCorp. Their forces are spread across three major regions: The mountainous, rocky Badlands, the frozen Fallen Wastelands, and the bizarre, colorful Tyrakian Territories. In each level, there are three Gate Keys to find, each guarded by a powerful Sentry Gun and numerous other foes. Find the keys, then find the exit. Do this for three levels and fight a boss. There are over thirty levels total and six Bosses. You have a wide variety of weapons to use, and a choice of three vehicles.
For its time, the game incorporated a number of cutting-edge features: Varied environments and terrain, terrain deformation, support for virtual reality goggles of the time, and cross-platform multiplayer between PC and Macintosh. The game worked on either system out of the box, and came with a multiplayer-only second disc that could be given to a friend. If you had enough discs to go around, 16-player deathmatches were possible.
This game shouldn't be confused with either film called Havoc. Or the Havok physics engine.
Havoc provides examples of:
- Alien Sky: In the Tyrakian Territories, the sky is pitch black.
- Bonus Stage: There's a bonus level after every Boss Fight. Collect floating crystals and "HAVOC" letters for bonus points.
- Brutal Bonus Level: It's incredibly difficult to actually gather all the crystals and letters, though this isn't necessary to progress.
- Boss Fight: Six total. Each is a different vehicle with wildly differing weapons and behaviors.
- Car Fu: Subverted, unfortunately. Ramming enemies (and terrain) tends to just damage your car without doing appreciable damage to them.
- Deflector Shields: Your vehicle has these, though they're really treated as Hit Points.
- Deadly Disc: The Disc Gun. Notable for it's very distinctive firing sound.
- Death from Above: The powerful mortar cannon gives you indirect shelling capability. Its fairly hard to use, though.
- Eldritch Location: The Tyrakian Territories, seen in worlds 3 and 6, are markedly different from the other two zones. Alien Sky, Amazing Technicolor Battlefield, Bizarchitecture and enemies resembling animals can all be found here, as can the game's two oddball bosses: A living cloud of flame and The Tyrakian Overlord.
- Enemy-Detecting Radar: You have a convenient minimap in the lower-right of your HUD. Targets are Color-Coded for Your Convenience: Land enemies are red, air enemies brown, sentries blue, static structures green.
- Energy Beings: The third boss is a giant, living cloud of flame that spits fire at you.
- Energy Weapon:
- The primary weapons are all this. In general, they possess a rapid fire rate and infinite ammunition.
- You begin the game with a weak red laser gun. One Power-Up you can find makes it blue and stronger, while another nets two lasers per shot.
- EMP: The first boss fires projectiles at you that scramble your targeting and radar.
- Flash Step: The second boss can teleport around in addition to ordinary flight.
- Improbable Aiming Skills: Of a sorts. A certain Power-Up vastly expands the range of the targeting brackets on your HUD, temporarily. Your shots auto-track enemies you keep within these brackets.
- Invincibility Power-Up: The "Ultrashield" Power-Up has this effect.
- Kill It with Fire: The slow-firing (relatively), but high-damage Fire Ball gun.
- Land Mine Goes "Click!": A Thermite Mine dropper is available as a secondary weapon. Watch out, as some enemies and bosses can also drop these.
- Mirror Boss: The fifth boss uses an identical vehicle and weapons to the player's.
- Power-Up: A staggering variety: Shield bonuses, Temporary invulnerability, new weapons, weapon upgrades and ammo, the "targeting bonus" and others.
- Scoring Points: The game tracks your score, arcade-style. You receive a bonus for finishing a level quickly, and can earn extra lives at certain scores.
- Sentry Gun: There are quite a few of these found on the ground and on walls, and they typically deal a lot more damage then mobile foes. A stronger, larger kind guards each Gate Key.
- Slippy-Slidey Ice World: The Fallen Wastelands, seen in worlds 2 and 5. Characterized by open clearings, large stalagmites and enemies with skis.
- Shockwave Stomp: The Shockwave secondary weapon. It fires a seismic pulse forward, much like the Thumper weapon in the later 1998 Battlezone remake.
- Stuff Blowing Up: Hoo boy. The secondary weapons are all explosive or otherwise highly destructive in comparison to the primary weapons, but have limited ammunition. Still, they are vital to your success, so don't be afraid to use them. But be careful, shrapnel from explosions can damage your vehicle. Keep a good distance from your targets.
- Randomly Drops: Curiously enough, the weapons, like other Power Ups. This means you might get a Disc-One Nuke or be stuck with the low-damage laser for one or more worlds. In addition, weapons used by bosses do not become available to drop until after said boss is beaten.
- Remixed Level: You revisit each of the three worlds.
- Videogame Lives: You begin with three, Scoring Points can get you more.