Round 21
This round contains six Iety, and six unnamed icicle-like enemies (which shall drop down upon Bob and Jim as they pass under them, and are worth 110 points when tapped for a kill); a P-Ball and Water Jar shall also appear at some point, which can be collected for a temporary power increase and speed increase respectively. The icy platforms are also automatically slippery - and once you clear this round, the screen shall scroll eastwards to the next one.
Round 22
This round contains seven Iety and eight (unnamed) icicle-like enemies; a Water Jar and Marmalade Jar shall also appear at some point, which can be collected for another speed increase and a power increase respectively. The icy platforms are also, again, automatically slippery (as is to be expected).
Round 23
This room contains three Iety and three Pegons (who shall slide their non-lethal ice blocks towards Bob and Jim); a Brown Hammer shall also appear at some point, and the three small platforms will also fall down when Bob and Jim hit them with their hammers (and stun any enemy they land on). The icy platforms are also, once again, automatically slippery - and swinging your hammer on the left side of the first platform also reveals the location of a third secret key. Once you've hit it enough times, it will fall down and land on your dwarf causing a pair of double doors to appear at the bottom of the screen; once either dwarf has entered them, they'll both fall down a long shaft to the third secret room (which is the first round in the game to feature ice blocks).
Secret Room 3
This room contains three unnamed icicle-like enemies, four Pegons, two Hiruda and one Crystalman; you must tap the 32 ice blocks with your hammers to destroy them, and the singular small platform will again also fall down when hit (and stun any enemy it lands on, except for the Crystalman who takes six taps to kill). Once you have cleared this room a chest shall fall down from the top of the screen - and once either dwarf has smashed it open with his hammer, it'll reveal one instance of every 100-point bonus item and a third 200-point crystal ball (but this one is coloured green instead of red or purple).
Round 24
This round contains six Iety, one unnamed icicle-like enemy and four Pegons; a King will also appear at some point, which can be collected for a freeze on every enemy (but, remember that it is only temporary, so do not hesitate in killing them). The icy platforms are also, yet again, automatically slippery.
Round 25
This round contains two Iety, two Pegons and three Hiruda; another P-Ball will also appear at some point, which can be collected for another temporary power increase. You must also again tap each of the 74 ice blocks with your hammers to destroy them, and the icy platforms are automatically slippery.
Round 26
This round contains one Iety and three Hiruda; a third Water Jar and second Marmalade Jar will also appear at some point, which can be collected for a third speed increase and second power increase respectively. You must also, once again, tap the 88 ice blocks with your hammer to destroy them - and the icy platforms are, for a sixth time, automatically slippery. The next round also contains a fourth key, that can be collected to go to the "Bonus Stage".
Round 27
This round contains six Pegons and three Hiruda; another King will also appear at some point, that can be collected for another freeze on every enemy. You must also, yet again, tap each of the 42 ice blocks on here with your hammer to destroy them - and the icy platforms are also, for the seventh time, automatically slippery. Swinging your hammer on the first platform also reveals the location of a fourth hidden key; once you have hit it enough times, it will fall down and land on your dwarf, causing a second pair of double doors to appear in the bottom-left of the screen. Once either dwarf enters them a curtain will come down from the top of the screen then slide to the left to reveal seventeen jars (all with rotating playing-card symbols in them) behind it.
Bonus Stage
Once Bob and Jim have dropped back down into view from the top of the screen, they shall have 60 seconds (1:00) to smash as many jars as they can and release their currently-displayed symbols; once that timer has run out, the curtain shall slide back in to the right as one (two, if Jim is present) nine-square grids come down from the top of the screen and tabulate the symbols that were released. You will receive 10000 points for every line you made with your released symbols - and a line, like in "Noughts and Crosses", can be horizontal, vertical, or diagonal. The game shall then resume as normal.
Round 28
This round contains six Iety and six more of those unnamed icicle-like enemies; a third P-Ball will also appear at some point which can be collected for a third temporary power increase. The icy platforms are also, for an eighth and final time, automatically slippery - so for the next round, they will not be icy.
Round 29
This round contains eight Crystalmen; a Gray Hammer shall also appear at some point, which can be collected for an increase to maximum power. The six small platforms will, once again, fall down when Bob and Jim hit them with their hammers - and, as mentioned above, the platforms are not slippery.
Round 30
This round initially does not appear to contain any enemies; however, the illusion will soon be shattered when the game's third boss, an enormous green hermit crab with extending claws, comes down into view from the top of the screen, and begins extending his claws towards Bob and Jim while dropping conch shells on them (which shall hatch into smaller versions of himself when they land, and send the ten pieces of their shells flying away off the top of the screen). You must also, for a fifth time, tap each of the 32 ice blocks with your hammer, to destroy them - and, you will have to tap the smaller crabs with your hammer to stun them, then pick them up and throw them at the large crab to damage him. Once you have thrown ten smaller crabs at him, he will explode, and you'll receive 5000 more points and go on to World 4; it's also worth noting that the harder version of this round has invisible platforms.