**In order to play multiplayer level 2-14, you must find the secret route located in 2-13. There is an area in 2-13 where a deep hole with a light bridge covering it seems to have no significance. Find and press the button that allows you to fall down the hole, and there's your secret level.
This achievement isn't as bad as it may first look. It can be done relatively easy with 2 players, as long as they both know what they're doing.
The achievement states that only 1 of the players is unable to splode. I do not know if both players accidentally splode, and then die, if the achievement still counts.
The toughest part is the beginning with the moving ramps, after this the level sort of shows you what you need to do. I do not have a video for this so bear with me.
To get this first part done, the player who IS sploding should hit the bouncer and land on the TOP ramp, furthest to the LEFT. This player waits while the non-sploding player hits the bouncer.
From here on out I will be referring to the sploding player as P1 and the non-sploding player as P2.
When P2 gets close to P1, but is still in the air, P1 must splode and knock P2 to the TOP CENTER ramp. Once completed, P1 will move to the BOTTOM CENTER ramp.
**Note, there is no BOTTOM RIGHT ramp.
P2 now falls off the RIGHT side of the ramp, and P1, who is below, splodes P2 to the TOP RIGHT ramp.
At this point, P2 continues to activate the barrels below for P1 to splode and press the wheel which eventually brings the platform down. The two players are easily able to just walk off the platform, when it reaches it's highest high, and land on the following platforms.
Like I said above, the rest of the level is fairly self-explanatory. The laser rappelling section requires P2 to just hang on, the game will do the work for you.
There is a section where both players are falling between sets of lasers, and eventually are shot from a cannon at a wall. This part is somewhat difficult because as you slide down the wall, if you go too fast you will hit the lasers below, and being unable to splode makes it tricky.
To beat that part, P2 must use the wall for a little while, until they are able to fall off and start sliding again on the vertical platforms. There are several times that the player must switch between sliding down the wall and a platform, then back. At the bottom there is a cannon positioned just about in the middle of the lasers you've been falling between.
The final test for the players is the finish, where once you have opened the light bridge, P2 must use the bouncer on the left to launch to P1, and P1 will splode P2 to the finish.
I hope this helps, and if there are any more difficult sections that I remember, I will add a solution to them.