It's not a cube, but this should work.
hide mouse
autocam off
sync on
sync rate 0
make object cone 1,100
scale object 1,10,30,10
xrotate object 1,90
make mesh from object 1,1
delete object 1
make object sphere 1,10
add limb 1,1,1
offset limb 1,1,0,0,15
make matrix 1,1000,1000,10,10
do
sync
move object 1,upkey()-downkey()
yrotate object 1,object angle y(1)+(rightkey()-leftkey())*.5
set camera to follow object position x(1),object position y(1),object position z(1),object angle y(1),60,20,100,0
point camera object position x(1),object position y(1),object position z(1)
loop