Defeat dorko with the hammer.

Yet another traditional achievement of mandew vs series.
Hammer destroys the boss's shell in one blow.
yet, the hammer power-up item basically only appears in the first half of 1-2.
so, important to keep the power-up until you reach the boss room.

Hammer power-up item basically only appear in this stage.
Get this first, then keep no-damage till the end.

The hammer item is above the checkpoint.
Be sure to arrive here with super mandew.
Avoid enemies and proceed safely.
Watch out for enemies that shoot fireballs!

Use warp below the second checkpoint.

Reach the goal instantly.
Never get the fire power-up item as the goal cloud prize.
Next is 1-3.

Hammer item will only appear in the goal cloud prizes if you arrive at this stage with hammer mandew.
You will never take any damage at this stage using warp, so essentially meaningless.

Use warp to skip entire stages.
As soon as level starts, hit the left edge of the screen with hammer.

You will arrive just before the goal.
There are no fire power-up prize in this goal cloud.
So you can touch the goal safely.
Next is the last, stage 1-4.

Rain leak occurs everywhere.
It is important to fix the enemy and moving lift cycles at this stage.
In the end, it's safer to keep running without stopping.

I recommend getting on the second moving lift coming from below.
This is to keep the subsequent trap cycle and timing in good pattern.

Jump from the rising lift to the ceiling at here.
Now you can ignore the trap and proceed safely.
If the timing adjustment is successful, you can move to the next 3 lift without jumping.

Here comes the danger zone!
At the end, the iron ball hallway.
The important thing is that YOU CAN KNOCK DOWN WRECKING BALLS WITH THE HAMMER!
So don't worry, let's move on.
It is also possible to run through the hallway.

Finally arrived at the boss's room.
Once the boss dialog window disappears, immediately run towards the boss.

If the boss stretches out his arm, this is the signal of the attack.
Do the dash hammer thrust at the same time as this signal.
If you want to do it more safely, wait for the boss to land and hammer him.
Rolling hammer is also OK, but it has less weak collision detection than dash thrust,
a bit less reliable.

If successful, all related achievements unlocked on the spot.

There is also my play video for reference.
Thank you very much for taking the time to read such a long guide!🙏
I hope this guide helps you :)