For the second game in the Mr. Do! series, the clown finds himself in a traditional platforms and ladders game. Each level is made up of six floors (seven including the castle's ramparts) and all are joined by a number of inter-connecting ladders. The ladders come in two different varieties: vertical ladders, which are fixed and cannot be moved; and diagonal ladders, which can be pushed left or right from the top of the ladder. This allows Mr. Do to reach other areas of the level and is sometimes necessary to redirect the path of any pursuing enemies.
The enemies in Mr. Do's Castle come in the form of unicorns, and as with the enemies of the first game, they will hunt down and try to kill Mr. Do. Replacing the 'Powerball' weapon of the original game, Mr. Do is now armed with a mallet. This can be used to temporarily stun the unicorns and buy Mr. Do some time to escape; but its primary function is to knock out the floor blocks that form each level's platforms.
Most blocks are marked with a cherry and collecting all of these will complete the level (on later revisions only, see Updates below). A level can also be completed by killing all of the unicorns. This is achieved by using the mallet to remove blocks and knock holes in the platforms. The unicorns will fall into any holes that the player has created; some simply fall through to the platform below, whereas others are trapped. Trapped unicorns can be hit with Mr. Do's mallet and knocked to a lower platform - useful for buying a few extra seconds for the player. If left alone, however, the unicorns will climb out, filling the hole in behind them, and transform into much nastier enemies. These new enemies cannot be stunned with the mallet and must be killed by dropping blocks onto them from the platform above.
Some sections of a platform have two 'skull' blocks at either end of them, with normal blocks in between. When both skull blocks are knocked out with the mallet, all of the blocks in between will fall to reveal wooden floorboards. This is highly effective in killing several enemies at once.
Each level also has three 'key' blocks. If Mr. Do knocks out all three key blocks, a large door opens at the top of the screen to reveal a shield which, when collected, turns the unicorns into 'Alphamonsters'. The Alphamonsters flee from Mr. Do and can be killed either with the mallet, or by dropping a floor block onto them from above. When Mr. Do kills an Alphamonster, its letter appears on a flagpole at the top of the screen. If the players collects all five letters, an extra life is awarded.
Barry Lewis holds the official record for this game with 421,780 points.
Earlier versions (including the Asian version, "Mr. Do! vs. Unicorns") :
* There are no cherry blocks, so hammering all the blocks is NOT a way to complete a level. At the start of each level, normal blocks will appear in the form of 'fill blocks' - those that appear in the later versions after unicorns have refilled holes. In addition, the colors on these blocks change after every two levels.
Later versions :
* Normal blocks now have cherries embedded on them at the start of each level. Hammering all of the cherry blocks is a new way to complete the level.
* The replay Diamond was added.
* Fill blocks no longer change colors after every two levels.
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 (later versions only) : 8,000 points.
TIPS AND TRICKS
* Make use of the rows of blocks marked with a skull 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.
* Blue unicorns are quite dangerous, and after a certain amount of time they duplicate themselves, so kill them as fast as you can if you don't want to be outnumbered!
* 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 hammer 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 Alphamonsters, 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.