Pitfalls of Life is the fourth stage in Stairway to Darkness, sub-chapter 21.
At the beginning of the stage, a Bore will spawn. Soon after, Sunfish Jones, the boss, appears. Later, another Bore spawns. Much later, another Bore spawns. After 3 Bores have been defeated, Bores will be spawned at a mild rate, about 1 Bore every 133 seconds. Squire Rels are spawed throughout the stage.
Begin the battle, spawn defensive meatshield cats, Crazed Sexy Legs Cat, Island Cat, and Crazed Whale Cat to defeat the Bore in the front, and spawn the Titan Cats (to damage the Sunfish Jones) if the next Bore has not reached the front yet.
After the player defeats 3 Bores, only spawn the Titan Cats because the respawn time for the fourth Bore is especially longer. Use the strategy above to defeat the fourth Bore and use the Titan Cats to damage the Sunfish Jones. By the way, if you want to finish off Sunfish Jones quickly, you may use Awakened Bahamut Cat to finish it off.
Or just use 4 meatshields with a Level 25 Momotaro and A. Bahamut.
Upgrade your Worker Cat until the first Bore is close to your base. When he's close, spam meatshields, Maximum the Fighter and send iCat. If you use iCat, there is a short gap where Bore will be able to attack. To prevent this, send 2 iCats. Momotaro will make this even easier, if he was used in the lineup. Use your other Ubers or attackers (but not Bahamut) to assist, and he will die in a fairly short amount of time. Once he's dead, wait for your Cats to get hit by Sunfish Jones, then send Awakened Bahamut. If you can, time your Cat Cannon to interrupt Sunfish Jones' attack so Awakened Bahamut has more opportunities to hit. By the time Bahamut dies, Sunfish should have lost a big chunk of his health. Stall him with Ramen until the next Bore comes out, and repeat the tactics you used to kill him the first time. Repeat this strategy as necessary, and the level will be over before you know it.
P.S. You can add Holy Valkyrie and send her to attack Sunfish Jones and if you are lucky she might freeze it, giving your A. Bahamut ample time to attack it.