Kartwars is a 2D battle game. You maneuver your Kart around the arena, scooping up boosts and hunting down enemies. Since your only goal is survival, you might choose to focus on defense, sucking up hexagons and stockpiling powerups. If you're feeling particularly bloodlusty, you can also go on the offensive, deploying your weapons to take out any enemy Kart that looks at you sideways.
Use arrow keys to move your kart. D uses items, S gives a turbo boost. You can also use the mouse to control your kart. Left cluck uses items, right click uses turbo boost. Glowing hexagons give you powerups or upgrade your weapons.
When you find a really great boost (such as the lightning cloak), don't waste time--go on the offensive and reap the rewards of your killing spree.