Need help with Sniper Achievement

[BlackLight78]

I completed this nice puzzle game. However, I have no clue, what I need to do in order to obtain the Sniper Achievement.

I killed big mama in the last (B-3) level by throwing a wooden block at her last form. If I try to do this by shooting myself at her with a cannon, then I can kill her, but cannot complete the level do the missing slime on the wooden block. Can anybody help me?

[Ozgarden]

It is in B-2 you have to kill Big Mamamia with Tetrobot in order to get the Sniper Achievement. If you kill her in B3 (Mamarina) , you won't be able to finish the level as you need to get a sticky wooden block to open the final door.

[BlackLight78]

Merci beaucoup. That worked perfectly fine!

[Seriousharry]

Killed in B-2 and no achievement...I need to kill her with Tetrobot? I killed with a block.

Nevermind... I killed with a block and with a block shooted with a cannon, but i need to kill her with myself shooted by a cannon. Done.

[swenor]

Originally posted by Ozgarden:

It is in B-2 you have to kill Big Mamamia with Tetrobot in order to get the Sniper Achievement. If you kill her in B3 (Mamarina) , you won't be able to finish the level as you need to get a sticky wooden block to open the final door.

I don't get it. To me it makes no sense. If I can choose to replay a level why would a later level affect a previous level?

I have just replayed B2 - I hit Momma 3 times as bot, and no achievo.
The description for Sniper is as follows:
Kill Big Mamarina with Psychobot

Since I'm (most likely) the Psychobot (I didn't read the story, so I might be missing the obvious) I met the requirements, so what's the deal?

[Ozgarden]

It's been a long time Bro,

Have a look at the walkthrough : ) Cheers !

[Berahlen]

Read the text carefully.

1) Big Mamarina is the B-2 boss, not B-3 (Big Mamamia).
2) Launching into her three times only reverts her to a normal slime -- to kill her, you actually have to hit her a fourth time.
3) To satisfy the achievement, the final hit has to be by launching yourself instead of just dropping a block on her.

[DALCOhstangultion]

EDIT: Yes, this Achievement basically boils down to pure, blind luck. There is no 4th cannon that shoots across her walking path. Basically, you go back to the third cannon and fire again. If you miss, immediately hit the Rewind button, wait a few more seconds than the previous shot, and fire again. Repeat as necessary while incrementing your firing delay.

OP: Is there a 4th cannon someplace that fires horizontally across her walking path? Or, are we talking about repeatedly firing vertically from the 3rd cannon (blindly, since she's off screen from there) and hoping our trajectory crosses her path when she happens to be in the right place? Surely this Achievement isn't pure, blind luck?