|N version||1.4 and later|
Sibilant S, the fifth level in Episode 67, is often considered one of the most difficult levels in the game.
This level is shaped in an s or snake, because a sibilant is a soft s sound.
Aries' Easy Way
This is a really tricky level, and it relies a lot on the principle of angle jumping. If you are on a slope, and hit jump, you will jump perpendicular to that slope(diagonally, not straight up). If you are running up the slope, you can jump to great height like this. If you are holding the direction running up the slope when you hit jump, however, you will not jump perpendicular, you will jump forward up the slope and not get much height.
The mine field uses this concept. You should get used to the normal angle jump by jumping over the first mine. From there, you need to jump to the ledge that sort of forms an enclosure with two top ledges. To do this, you have to be pretty close to the bottom ledge, because when you hit jump, you will jump diagonally up and right, and you don't want to hit that mine that is just to the right of the enclosure. So just hop close to the ledge, and steer left onto the ledge.
From there, you have to move quickly, or you'll get killed by the gauss turret. Jump to the right onto the slope, and watch your head, because if you jump right and hit the ceiling, you'll lose heigh and run into a mine at the base of the slope. So jump quickly onto the slope, and keep your momentum going up the slope. Once you get close to the mine that is about 3/4ths of the way up the slope, let go of the right button and hit jump. You want to do this quickly, so you jump with all your momentum still intact. If you did this correctly, you should get quite a bit of air jumping diagonally up-left, and you should be able to steer hard right, going over the mine (usually there isn't a lot of clearance room, so this is a tricky jump all about timing). If you didn't let go of right and hit jump, you'll jump up and right, and blow up on a mine.
Once you clear the mine, keep moving right to avoid getting killed by the floor guard and turret, and jump to the door(you got one of the switches, right?). My favorite switch to get is the one between the thwumps, because it's easy to get, and you can just jump right over the remaining switch-doors and get to the door(also you're protected from the turret if you go for the gold, but the floor guard can still get you).
Method 2 (Easy)
If performing a perpendicular jump is too difficult for you, instead just tap a light jump between the two mines at the end of the slope, and then immediately jump again to get out of the way of the floorguard (all this time avoiding the gauss turret).