The sequel to Mr. Do! sees the clown's return, this time not armed with a ball but with a hammer. Mr Do! must climb the ladders in the castle, using the hammer to smash the cherry blocks and to knock them onto the pursuing unicorns. The level ends when either all the cherry blocks are knocked down, all the unicorns are killed or an extra life or free game are collected. The unicorns fall into gaps where the blocks once were, and Mr Do! can knock the block from above onto a unicorn while it is trying to climb out of the hole.

There are three types of unicorn: red, which are the basic ones and fairly dumb; green which chase you directly; and the blue ones which are high-speed, cannot be hammered down through a gap and divide into more unicorns up to a maximum of 8 pursuing you relentlessly.

There are three blocks on each level marked with a key and when all of these blocks are knocked out, the door at the top of the castle opens. You can then collect the cross which appears in the open door, and all the unicorns turn to EXTRA letters for a short time which can be hammered to spell out an extra life.

There are diagonal ladders on the level, and you can push the top of the ladder to position it next to the adjacent platform.

Occasionally a block when knocked out will reveal a diamond which can be collected for a free credit.

Knocking a block onto a red unicorn below so it falls one level: 500 points.

Knocking a block onto a red unicorn below so it falls two levels: 1,000 points.

Knocking a block onto a red unicorn below so it falls three levels: 1,500 points.

Knocking a block onto a red unicorn below so it falls four levels: 2,000 points.

Killing a green unicorn: x2 points.

Killing a blue unicorn: x3 points.

Killing 2, 3 or 4 unicorns with one block : x2, x4, x6 points.

Collecting the free credit diamond: 8,000 points.

Different (probably earlier) version called Mr. Do vs the Unicorns. It has significant differences in the gameplay.

Another alternate version.

Starting lives can be set to 2, 3, 4 or 5 (default is 3).

Game difficulty can be set to easy, medium, hard or hardest (default is easy).

Extra life can be set to easy or hard (default is easy).

Make use of the rows of blocks marked with a skull block at each end. Knock out one skull block and all of the middle blocks, wait for unicorns to fall into the gaps and knock out the other skull block. This will cause the whole row of blocks to fall, killing all unicorns in the holes and below.

Use your hammer to briefly stun a pursuing unicorn, allowing you to escape.

If a unicorn is chasing you up a diagonal ladder, push the top of the ladder away when you reach the top so the unicorn ends up on a different platform.

You can kill a unicorn on the same level as you if he is standing on a block when you hit it. The unicorn will fall and you will be awarded the same score as if you had knocked the block down onto the unicorn.

If a unicorn is filling a hole vacated by a block, you can hemmer it to knock the unicorn down to the next level. Note you CANNOT do this to a blue unicorn.

Wait until all unicorns are as close as possible before collecting the cross to turn them into EXTRA letters, giving you more chance to kill more of them.

You can fall from any height and will not die so jump down through gaps to avoid unicorns.