|back and forth|
|N version||1.4 and later|
back and forth is considered one of the hardest levels of the game, the reason being that the space is very limited, but there are a huge number of mines and zap drones (luckily, unguided) patrolling the small area. (A lot of) Patience and practice are necessary to beat this.
The green path represents the path to follow, blue indicates the paths of the drones when they are relevant to your current position.
Get the door switch to your right, then immediately hop over to the left depression and jump against the left slope of that depression. This should lift you over the zap drone passing below. Be careful not to do a perpendicular jump as you will crash into the mines on the ceiling, and if you leap forward you will be crushed by the drone. There are alternative ways of getting past this drone, including walking underneath it and other ways of jumping over it. Get to the left wall, jump against the corner (slipping past the 2 drones moving downwards), and then walljump off to the top level. Leap over to the area containing the exit. Wait for the drone there to enter the area with the door switch and then leave, then run into the switch.
The drone you just met will now be at the top of an alcove of the ceiling. Quickly run down the door switch slope and jump on the flat part to get over to the left side (jumping on a slope will cause you to hit the drone). Go down (there will be a drone coming up on the right side of the shaft, though it shouldn’t bother you).
Now two zap drones are headed in your direction! One of the drones will detour into the depression while the other one will head straight towards you. Jump over the first drone (without moving anywhere horizontally), and then almost immediately again jump over the second drone as it approaches you. Land on the left slope of the depression and jump across to the next door switch.
After getting the switch, run down the slope to the flat part of the depression, then jump over the drone in the left depression. The switch you just opened has unfortunately also opened up the other four zap drones into play! As you climb up the left wall, you will notice that two zap drones are headed your direction, with very little gap in between.
You could rush this part and squeeze between them, but that is slightly difficult to pull off. Instead, it is easier to just wallhang until both drones pass by; then jump into the left depression on the top level. Another drone will pass by above you. After it leaves, jump over to the right side to get the last switch. Enter the right side of the level for the first time. There is plenty of gold, but there are also more mines.
A drone will be immediately approaching; jump completely clear of it to the left slope of the rightmost depression. From there, jump to the right wall, and then just cling onto anywhere on the right wall. Two more drones will pass by to your left, then quickly descend and jump over. Another drone will be coming from the left, and one from the right. Jump over the drone coming from the left and then leap to the exit switch.
Another drone will be heading right towards the exit switch from the left side, threatening to trap you in there; quickly dash out and jump all the way to the left shaft. Climb the left shaft (wary of the single drone coming downwards).
To make your life even more miserable, you will find that there will be a drone trapped in the little area around the exit! With very careful maneuvering (it really sucks to die here), let the top drone go by you, wait for the drone at the exit to be in a position so that it won’t interfere with your completion of the level, and tap jump into the door.
If you are still having trouble with this level, remember that a ton of patience is necessary. Do not get frustrated over bad/accidental jumps, etc; instead learn from those mistakes to develop an algorithm to beat the level. There is also a demo here which can follows the above path exactly, if you're having trouble with the above diagrams.