- Plan of Attack
- Watch out for the steam rollers, and head to manhole C.
- Fight Bebop the sewer and chase Rocksteady out through manhole D.
- Enter manhole G and exit through manhole H.
- Enter building I, and defeat Rocksteady to rescue April O'Neil.
While walking around outside, you face two dangers; foot solders and steam rollers. The foot soldiers outside are easily dispatched with a single strike from your weapon. On the other hand, the steam rollers will flatten you in an instant no matter how much health you have, so steer very clear of them.
In general, reserve Donatello for important fights, and use the other turtles to travel from one location to another.
Manholes A and B
This stretch of sewer is completely optional, and you can bypass the two manholes on your way to manhole C. However, skipping this means you have to avoid getting squashed by the roller in the Area 1 overworld. If you do choose to pass through it, there is a Foot Soldier mid-boss fight about half way through. A slice of pizza can be found just to the left of the ladder to manhole B.
Manholes C and D
Whether you pass through the sewer connecting manholes A and B, or simply walk around the outside, you'll have to pass through manhole C to proceed. The beginning has basic enemies, but when you reach the far right side, you'll encounter Rocksteady and Bebop. Rocksteady will be up on the ledge holding a tied up April O'Neil hostage.
Bebop will engage you on the ground below, attempting to charge into you from a distance. You should switch to Donatello to take advantage of his weapon's reach and strength. Strike Bebop with Donatello's Bo, and move out of the way or jump over his charge. It will only take a few strikes to knock Bebop out. Then Rocksteady will pick up April and move on. Chase after her through the door, and you'll arrive back outside near manhole D.
This building is optional. It contains a slice of pizza, as well as an entire pizza, but you'll have to fight your way through narrow passages to get them. In all honesty, the pizzas are not worth the effort, considering you can recharge much more easily by grabbing the slice that appears continuously near manhole G.
There is very little point in visiting the sewer below manhole F. It dead-ends after a long journey to the right. The only nice thing about it is the invincibility icon about half way in, which gives you the ability to crash through all of the enemies, including the frog mid-boss if you get to the very end quickly enough. But then you have to double back and return the way you came.
Manholes G and H
The slice of pizza by the ladder to manhole G is a great way to restore any lost health to the entire team. Pick up the slice for any turtle that needs health, then exit back up the ladder and jump back in again, and the slice will always return. After filling all your turtles up with health, make your way to the left. About half way in, you'll be forced to fight against a chainsaw wielding mid-boss. Use Donatello to take him out, and then continue to the ladder on the left. Climb up through manhole H, and you'll arrive just outside of building I.
The enemies here are very powerful in the early game, so proceed with caution.
You'll enter on the first floor of this building, and you must make your way to the right. Many flying creatures will move back and forth above the conveyor belts. You can use Donatello's staff to try to remove some of them before jumping up to the first conveyor belt. More flying creatures will appear as you continue, and a robot guards the floor between the two conveyor belts. As you cross the second belt, it's possible to leap over to the platform with the ladder in order to avoid fighting with the two boomerang henchmen that try to stop you.
Climb up the ladder, where you'll encounter another boomerang henchman and two flying creatures. Clear them out and them climb up and over the boxes. Walk to the left side of the second floor, and Rocksteady will attempt to ambush you. He likes to charge like Bebop did, but he also resort to shooting at you with his gun. Once again, Donatello has a big advantage against Rocksteady over the other turtles, so he's a good pick to knock Rocksteady out. It's even possible to hang out on top of the boxes where Rocksteady can't hurt you, and continuously strike downward at him until he is defeated.
Upon beating Rocksteady, you will go an untie April, who warns you that Shredder is trying to blow up the dam.