orxVECTOR tilePos;
orxVector_Set(&tilePos, orx2F(80.0f) * x, orx2F(160.0f), orxFLOAT_0);
orxObject_SetPosition(tile, &tilePos);

orxVECTOR pos;
orxObject_GetPosition(player, &pos);
pos.fX = -pos.fX;
orxObject_SetPosition(player, &pos);

Rotation is set in radians. Zero rad vector is equivalent to (1, 0) vector in screen coordinates. In other words it is a horizontal line pointing from left to right.

Positive rotation is set in clockwise direction. If vector origin was in the center of the screen, then 1 rad would point to the left right corner of the screen.

Set angular velocity changes object rotation value over time. Setting positive value make object rotate clockwise. Negative value sets counterclockwise direction.

TBD: What's the unit of measure?

By default object starts with zero rotation angle. Rotation counterclockwise will put the angle into negative range. Rotation clockwise will put the angle into positive range of values.

Returns current object rotation value in rad. The value returned can be any floating value.

See orxObject_SetRotation for coordinate system reference. See orxObject_SetAngularVelocity for discussion of continuous rotation.

Use it to obtain objects within the specified bounding box.

    orxOBJECt *obj; // comes from mouse click event or in some other way
    orxVECTOR pos, size;
    orxFLOAT range = 250.;
    orxOBOX box;
 
    orxObject_GetWorldPosition(obj, &pos);
    orxVector_Set(&size, range, range, 0.);
    orxOBox_2DSet(&box, &pos, &orxVECTOR_0, &size, 0.);
 
    orxBANK *neighbors = orxObject_CreateNeighborList(box);
    void* cell = orxNULL;
    while ((cell = orxBank_GetNext(neighbors, cell))) {
        orxOBJECT **n = cell;
        orxLOG("object name: %s.", orxObject_GetName(*n));
    }
    orxObject_DeleteNeighborList(neighbors);

Object Traversing has its own page due to somewhat large discussion on the topic.