Bionic Seaweed is the second stage in Quarantine Isles.
This is one of the levels where Banner Cat can really shine as his weaken will help you keep them in control and his higher proc rates and short recharge time can make them weaken the enemies forever. Bring anti-metal cats and critical hitters as well, as you will need them (however,Tesalan Pasalan isn't very useful here due to the high amount of peons in the way).
Tip: Catornado and E. Kubilan Pasalan might not be a good choice as a critical hitter in this level. Because of Catornado's area attack and E. Kubilan's waves, as they have a tendency to take out the metal doges too early and have the Super Metal Hippoes stack with the Metal Seals.
The general idea here is to bring many meatshields and fill the remaining slots with crowd controllers and critters. Stall the metal one horn and the metal doges for money. When you hit the base, lure the Sir Metal Seal to your base, then spam everything, possibly with a CPU.
Strategy 1 (Ft. Seaside Neneko)
Bring 5 meatshields, including Pair Rope Jump Cats, Waitress Cat (at least level 30), Seaside Neneko (at least level 25 is recommended) and two other critters of your choice with reasonably high crit chance. The last slot can be filled with Banner Cat or any other cat of your choice. Set your cannon to Waterblast.
Kill the Metal One Horn but don't send out your 100% critters yet unless you're in immediate mortal danger; stall the Doges until you have plenty of cash and you've upgraded Worker Cat a couple times. When the Super Metal Hippoes and Sir Metal Seals come out, start meatshielding like crazy to protect Waitress and Neneko. They both should be able to get at least one critical hit in each without dying. If your cats are leveled high enough, you should prevail.
Strategy 2 (2 and 3 Star)
Lineup: Manic Mohawk Cat (30), Eraser Cat (20+27), Manic Eraser Cat (40), Catasaurus (26+4), Mochi Cat (25), Hoopmaster Cat (25), Curry Cat (30), Zamboney Cat (30), Manic Island Cat (30), Soba Cat (30)
Cat Cannon: Waterblast
Battle Items: Cat CPU (Recommended)
Start off the battle by upgrading your Worker Cat a little and then send out a Soba Cat, she can solo the Metal One Horn, making him not an issue. Once the Metal Doges arrive, send out some meatshields and then Zamboney, Catasaurus, Hoopmaster and then Mochi. Only one Catasaurus is needed to kill all the Metal Doges, so don't worry. The Metal Doges should respawn shortly, unless your RNG was so good that you killed all the Metal Doges to fast and activated the boss wave to early, if this happens, just force quit and try again. Repeat the process of killing the Metal Doges until you get to max Worker Cat and close to max money, you don't need max money exactly as every unit in the team is fairly inexpensive. Once you hit the base, it's really just kind of spam everything, hits from Soba are the most crucial to get right, but if a Metal Doge gets in the way, then there is nothing really you can do about that, this is an RNG battle so this strategy may not work the first time because of that, but there is nothing you can really do about that, the second most crucial hit is a crit from Manic Island, if he does crit, then that is HUGE and can easily do massive damage to the metal he hits. So just really, spam until you win. If you are struggling a lot though, I would recommend using the CPU like I put up there before. A way to make this strategy a lot more consistent is by getting Talents on your Catasaurus or putting some more levels into your crit units, other then that though, if you don't get it the first time it's most likely not your fault. But after a good run where you actually get crits, you will have won the level!