Harry Tunnel is the third stage in Jail Break Tunnel.
3 Korys appear as the main threat when you attack the base.
Cat Lineup: Crazed Wall Cat, Eraser Cat (level 20+19 at least), Macho Legs Cat (level 20+19 at least), Crazed Sexy Legs Cat, Paris Cat, Crazed UFO Cat, Crazed Dragon Cat, King Dragon Cat (level 20+16 at least), Valkyrie Cat and Bahamut Cat.
Begin the battle, spawn Crazed Wall Cat and Eraser Cat for defense and use Macho Legs Cat, Crazed Sexy Legs Cat and other long-range cats, trying not to hit the enemy's castle.
When the player has maxed money capacity, spawn all cat units, (stop spawning Eraser Cat and Crazed Wall Cat because they have close range attacks, as Kory's attack will create shock waves and hit the other cats behind them. It's recommended for the player to use Dark Cat instead.
After defeating all the Korys, start spamming the Wall Cats.
Cat Lineup: Only 2 Meatshields (Crazed Macho and Crazed Wall), Bahamut Cat, and fill the rest with cats with high range, such as Paris Cat, Macho Legs Cat, Drama Cats, Drama Cats, and Cameraman Cat
First, spam the meatshields and slowly fill up your wallet. Then spawn Bahamut Cat. You have to get all of your meatshields killed once your units hit the enemy base.
After the Korys spawn, try to get a lot of attacks or knockbacks on them. When your damage dealers are all dead, spawn Bahamut Cat again near your base to finish them off. Then beware of the magnified Black Gories and Duches and push forward.
Strategy 3 (Speedy Units)
This strategy requires you to beat ItF Chapter 3 first. (I suggest you beat that chapter because its not that hard to beat when you have Max Anti-Alien treasures and some Ubers)
Cat line up: Crazed Wall (20), Ramen Cat (32), Lion Cat (20+13), Crazed Giraffe (20), Cat Eastwood (15), Crazed Sexy Legs (18), Akio Yabe (30), Jamiera Cat (20+11), Holy Valkyrie (30), Awakened Bahamut Cat (30) The ones on Italic are not important, can be replaceable.
First, stall the peons with anything other than Valkyrie and Bahamut, but dont go too much. You wanna save at least 7500 money to deploy both Valkyrie and Bahamut at the same time. When your have a lot of money, spam all the cats. When Kory appears, Bahamut should do a lot of damage to him. If Bahamut dies, stall the kories with all of your cats until you can spawn Bahamut again.
The Lion and Giraffe cats are for dealing damage while stalling the Kories.
Strategy 5 (Mostly Low-leveled Cats ft. Octopus Cat)
Like the strategy above, beating ItF Chapter 3 is required.
Cat line up: Macho Cat (20+7/8), Crazed Cat (1), Crazed Wall Cat (20), Eraser Cat (20+11/12), Ring Girl Cat (30, if you don't have her replace her with something that can consistently kill Gory Blacks), Octopus Cat (30), Cameraman Cat (30), Cyborg Cat (30), Holy Valkyrie Cat, Awakened Bahamut Cat.
Note: Getting some Itf Void fruit treasures and maybe Sky Fruit treasures is recommended to counter the Owlbrows and Gory Blacks.
Send out meatshields at first. Once Gory black appears, start sending your Gory Black killer, and begin to spawn Octopus Cat. Don't rush and instead, wait up to level your wallet, which should be quick since most enemies here drop high amounts of money, and stack units with +340 range. Once your wallet is leveled to 8, begin spamming and push to the base, and once you're about to hit the base, send Awakened Bahamut Cat. Octopus should block the waves while Awakened Bahamut and your hitters deal with the Kories.
Strategy 6 (No Waveblocker, light meatshield)
Use 2 very weak meatshields so they never survive more than 1 hit from the Kory. The Gory Blacks may end up killing them before the Kory can proc the shockwave. You'll need at least one anti-black unit but having more than 1 is fine too as long as they're beefy or rather long range+aoe. Use C. Bahamut instead of A. Bahamut as he outranges the Owlbrow.
Start off by stalling as usual and spawn a Pizza Cat or other to help clear the Dark Doges without pushing too hard. Once you get a bunch of cash, spawn your longer range heavies and then start spamming Samba Cat and Macho/Crazed Cat. The long chain of Samba Cats will help to stall the Kory/Gory Blacks long enough to work the enemy down.
The more long range damage dealers and ubers you have, the better. The lower level and weaker the meatshields, the better. This is why Samba is chosen over Eraser.
Strategy 7 (4-star. No melee meatshields)
Any Cat Combo (I used Research (L)
The key is to create a large stack of range attackers before you reach the enemy base. Camera Cat as a dual purpose of ranged meatshield that can attack Kory without being attacked, and would most likely die or get knocked back before Kory can strike her to create a shockwave. Li'l Macho Legs is actually a second layer of range meatshield to protect the primary attackers (Li'l Dragon Cat, and Cyborg Cat) since it doesn't outrange the Owlbrow. Crimson Mina is mostly there as a strong LD unit when you reach the base.
Start by spamming Camera Cat and upgrade your Worker Cat level when you can. Use Cyborg Catif you are about to get overwhelmed but make sure to some of your cats die if they are starting to push too far. Once you hit level 8, start spamming Camera Cat non-stop. As soon as you hit a quarter way away from your base, spam the other 3 cats but don't summon Crimson Mina until you reach reach about 1/2 of the way to the enemy base. Note that if you hit the unit limit, stop spamming Camera Cat.
By the time you reach the base, you will have a sizable stack of range attackers and ranged meatshield. The Kories should never proc a shockwave as the Owlbrows and Gory Black will strike the Camera Cats back.