RTA Guide/To the Top of the Fortress
To the Top of the Fortress is the second mission in Whomp's Fortress. The 2nd star must be selected when entering the stage in order to spawn the tower while not spawning the owl.
You can stay in C down for an easier view, but the C-up does reduce lag significantly.
The longjump up the slope can also be used as a backup when the stairs eat your jump on the fence clip strat.