Once again undaunted by a seemingly impassable obstacle, Casey's engine struggles, huffing and puffing, up the side of the gorge and continues on its way.

I cried in a passion, finding myself suddenly confronted by an impassable obstacle.

However, Russia's existing economic system, which lacked a sizable middle class and which relied on forced labor, was an impassable obstacle to the development of a free market.

Few fortifications exist on the east side, as the sheer cliff of the Rock of Gibraltar is a virtually impassable obstacle.

Without the fish ladder it would have been an impassable obstacle for the migrating salmon.

These vehicles now created a nearly impassable obstacle to movement.

He cut off the deadly pulse of death that had made the fence an impassable obstacle.

So tankers tried going over or through the embankments, but the hedgerows were almost impassable obstacles to the American M-4 Sher-man tank.

But our upward march was soon stopped at a height of about two hundred and fifty feet by impassable obstacles.

Flipping therefore allows the player to maneuver around obstacles impassable in the 2D perspective, or find items, enemies or varying landscapes only visible along the z-axis.