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, A Uber Rare Cat, and fill the rest with cats with a range of over 300, such as Paris Cat, Macho Legs Cat, Drama Cats, Dancing Master Cat and Kasa Jizo.
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.
Cat line up: 3 Cheapest meatshield + Artist cat (optional?), Paris Cat, Drama Cat, Urashima Taro, Anubis, Bahamut, Unknown Cat (ANY other uber will be better).
Spawn several meatshield and paris to stay alive while upgrading worker cat to MAX. Keep enemies close to cat base. Then stack Urashima Taro, Paris Cat, Drama Cat (when enemies are kept close when start stacking, stacking is easier). Then spawn Unknown Cat, then Bahamut. When the cats almost reach enemy base, spawn Anubis. Hopefully your cats can knock back Kory and attack the base as much as possible (I managed to kill all Kory a few moments before the base was destroyed).
Holy shit, whoever wrote the one above is mighty ubercarried.
Strategy 4 (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 (28+4), 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 Macho Cat, Crazed Wall Cat, Eraser Cat (20+11/12), Crazed Sexy Legs Cat, Octopus Cat (28+2), Power Driller Cat (10), Kasa Jizo (15/16), Holy Valkyrie Cat, Awakened Bahamut Cat.
Note 1: Power Driller Cat can probably be replaced, It didn't help me out too much.
Note 2: If the player does not have Kasa Jizo, a good cheap anti-black cat is recommended for the Gory Blacks. If it is high-leveled then it is much better.
Note 3: For the Cats whose levels are not stated, they are 10 for the Crazed Cats and 20 for the Special Cats. If the player has higher-leveled cats then these, it will greatly improve chances of winning.
Note 4: The player might need to try again or use Cat Food to continue, because the battle can get rather close and this strategy may not always work effectively for the player, so having some Cat Food ready just in case should work. This is, after all, a mostly low-leveled strategy.
Note 5: This strategy takes rather long, probably just shorter than 15 minutes. Hence, you may or may not see Ms. Sign, but do not be discouraged if you do!
Note 6: Getting some Itf Void fruit treasures and maybe Sky Fruit treasures is recommended. I had maxed out treasures in Chapter 1 and about 50-65% of each in Chapters 2 and 3.
First, Send out Eraser and Crazed Wall, With Crazed Sexy Legs. Continue sending out Crazed Sexy Legs. When the Gory Black comes, Send out Holy Valkyrie with 1 or 2 Jizos, or your anti-black cat. Power Driller Cat should be sent out around this time. The first Gory Black should die soon, along with the other peons. When each Gory Black dies, another will spawn. Meatshield sparingly, as you do not want to go too far and hit the base. Start sending out Octopus Cats at this time. Besides blocking Kory's shockwaves, Octopus Cat helps with the Owlbrows, taking 1/4 damage (1/5 with all Itf Sky Fruit treasures maxed) from them and reducing their attack by 50% every so often. If the player's research is good enough, another Holy Valkyrie Cat should be available by the time you have max money and are almost at the base, with about 3-4 Crazed Sexy Legs cats. When the Korys spawn, send out Awakened Bahamut to take some health off of them.
After a while the Gory Blacks will start breaking through your defenses (if not the player is a better meatshielder than me...) Stall as much as you can. Keep sending out your anti-black cat, Octopus, and Holy Valkyrie if you get her. Power Driller Cat is somewhat optional at this point because of the Gory Blacks. With some luck, Holy Valkyrie will remain protected behind Octopus and freeze the Korys every so often. After a while, the enemies should be almost at the player's base. Thankfully, Awakened Bahamut should respawn around now. Send him out with some timing and more health can be chipped off from the Korys and they will be knocked back. Never stop sending all the other cats!
After 1 or 2 more Holy Valkyries, your cats will start to push back. The Korys will slowly die, and all that stands in your way are the Gory Blacks and other peons. As your cats start attacking the base, another Awakened Bahamut Cat will spawn. Use him to rush the base.
In total, the player should have spawned 4-6 Holy Valkyrie Cats, and 3 Awakened Bahamut Cats.