lol... nice tip

Try to avoid levels 72 to 76... the other ones are easy

(so anything that ends one of these levels is good! Even these ones:

)
And - important: End level 71 on the LEFT side! Otherwise you will be in a not-so-funny place in level 72... And: Don't die in level 72, or you will respawn exactly at that place...
Nothing more to say... it's mostly training

level 78 for example is quite easy when you got through it a few times... Before that, when you die, get to the teleporter as quick as possible, before the protection shield wears off.