Community Badlands (Arena) strategy

General

As the map has many twists and turns, Demomen and Heavies can be highly useful, especially with a Medic on the team.

Unlike in other versions of Badlands, the arena version has water, located under the small bridges by the spires.

As a Soldier, Demoman or even a Huntsman Sniper be sure to spam enemy choke points such as the enemy house entrances with rockets, rollers or arrows this will block off the enemy and maybe get you some kills as well.

The Scout's extra speed allows him to quickly loop back behind the enemy team by running under the bridge to flank the enemy team.
The house is a very tight area, crippling the Scout's ability to dodge enemy fire.

The crates by the control point can be used to gain a minor height advantage. This will allow you to get the maximum amount of splash damage on the enemy.
Rocket jumping costs a significant portion of the Soldier's health and should be avoided unless Medics or Dispensers are available.

Badlands has many open spaces that allow classes with ranged weaponry to harass Pyros very effectively. Scouts are particularly dangerous.
The Axtinguisher allows Pyros to make fast, clean kills without taking much damage.
The First Blood critboost effect significantly extends the effective range of the Shotgun.

Sticky traps can be effectively placed on the left side of the enemy house to thwart incoming enemies.
Enemies coming out of the valley across the bridge from the house have a lot of cover to hide their approach, but well-placed stickies will make their stay a short one.

A good Sentry Gun location is peeking out of the window at the balcony. With control over the central battleground, and a decent ammo pickup nearby, it's an effective location.
Dispensers placed in the building by spawn or in your house provide your teammates with a safe place to heal and to restock on ammunition.

Due to the open nature of this map, Snipers are useful, with the two main spots being at either end of the Control point bridge or in the lower area underneath the bridge, both giving the Sniper a view of large areas of the battlefield where he can pick of enemies with ease.
You can be invaluable in the end game by hitting Engineers turtling by spawn. Sit by gray bridge and pick them off while staying out of range of their Sentry Guns. Watch out if the Engineer is using a Wrangler as this can have fatal consequences.