The room below will be swarming with Seeker type enemies, scanning the arena with their pesky green lasers. A short cutscene will draw your attention to the scene outside, which will suddenly devolve into chaos. A statue will topple over heaving the area strewn with rubble. Get up and head down the hall to the right. More chunks of statue wil blow in through the windows and the walls. Round the corner in the hall ahead and drop down the hole in the floor. An Energon Cube will lie in the corner directly ahead. Grab it if you need it and then head over to the left side of the room, where you will find another hole leading to a lower floor.
Head into the hall ahead and wait for the Seeker to pass by to the left. Approach his back and hack him up with an execution. Then head into the air duct to the right and pop out behind a second Seeker. Hit X to execute the second enemy and proceed through the doorway to the right. This will lead you into a room occupied by two Seekers. There are two ways to deal with this room. First, you can run directly in and hide behind the small barrier right behind the first Seeker. If you do this fast enough, the Seeker won't see you and it will eventually turn and investigate another section of the room, at which point you can take out the enemies one by one. Second, you can pause in the hall before heading into the room and wait for both of the enemies to turn their backs. Then, cloak and rush in for two quick kills.
Head to the opposite side of the room and pull the switch to open up the large circular door to the next area. Proceed down the hall ahead and sneak up behind the guard. Execute him and grab the ammo from behind where Jazz lies trapped, and then hit X to free Jazz. He will open a path for you ahead which you can run up to get to a hallway. This hallway leads you outside, where you will encounter a group of flying Decepticon snipers. Use the larger stone slab to the left for cover when the snipers get you in their sights. You will know that they are targeting you because the faint purple beams will slowly congregate on your location. The snipers will fly from position to position, never letting you get a solid bead on them for too long. For this reason, you should try to focus on one at a time and go for headshots so that you can kill them before they change locations. Once both of the snipers are dead, loop around the coliseum and head through the entryway on the right side.
An Energon Cube will lie directly to the left of the entryway, and more enemies will lie just beyond, so you might want to refill on health. Cloak yourself and make your way to the back of the room, and fight your way from the back to the front of the room using one hit kill executions to carve your way through the opposition. Jazz will pop out when everybody is dead and open up a path on the left side of the room. Follow him down to a large blockage formed by a giant rock formation. Strap a charge onto the rock and blow it up, heading through to the left to find Armory pods and money. Then, head through the right doorway to find two more of the Armory Reactors before heading over the catwalks. On the left side of the catwalks, you will find an Energon Cube and a locked door. Wait for Jazz to open up the door and then head through, grabbing the blueprint from the wall on the right and using the store on the left if you need it.
When you are ready for a fight, head outside and take cover behind the low wall ahead. Snipers will fly into the large room ahead and take up positions on the walls and columns. You may not have a long range weapon equipped right now; if you want one really badly, check the store in case you have anything longer range in there. Otherwise, just keep up a concentrated stream of fire as the snipers fly about in the room ahead. Once you have killed all three of them, drop down to the floor below and climb up the ramp directly ahead. If you need ammo, plenty of it is scattered about the floor below. Be careful though, as more Decepticon troops will soon be rushing in on the second floor. They will meet you on the first floor if you don't hurry up. Only a few of them will come out, and they can be easily shaken with a quick cloak pop.
Head upstairs over the catwalks and across to the other side of the room. The room on the other side of the catwalks will have another enemy or two in it; you can surprise them by cloaking and popping up behind them for quick instant kills. In the next room, a sniper will ambush you from overhead. Shoot him down from the ceiling with a quick headshot, and then proceed to the right to find a room with some nifty currency crates and weapons and ammo in it. Loot everything and equip new weapons if you want to. Leave through the opposite side of the room, where Jazz will swing off to the next area leading you onwards. A store will await you to the lower right if you need to fill up on any consumables or ammo.
Proceed into the caged room ahead of you and flip the switch to bring an engine down on to the cart ahead of you. This will lower it, along with you, down to the bottom floor. You will now have to protect the bomb while it makes its way towards the obstruction ahead of you. This checkpoint will be a pretty tough one, so you will want to hold up for the long haul. If you are having trouble, you will want to visit a shop before trying again. As you lower down to the bottom floor, an enemy will run out from behind the right column, followed immediately by one from behind the left column, and then one shotgunner from the direct center. At this point, enemies will begin attacking you from the catwalks above you as well. This is about the point when things will start to get a little too chaotic to keep a hold of. You will want to deal with the charging shotgunner as soon as humanly possible, and then follow that up with a quick kill to the enemies above you. Around this point, more enemies with shotguns will be rushing in from either side.
Stay nimble and dodge constantly during this battle. Absolutely do not let the shotgunners get close to the bomb; they can dismantle and destroy it in a few shots easily. If you have any grenades or similar consumables, like the mines, chuck them out and let them scatter the battlefield with parts. You can even back yourself into a corner and pop a shield to block the enemies, but note that their main target will be the bomb at this point and not you. An alternate option would be to pop a shield behind or to the side of the bomb, which will protect it from that angle of attack temporarily as it moves forward.
When the bomb reaches its destination, you will have to mop up all of the enemies remaining in the arena before setting it off. This shouldn't be too tough now that the enemies aren't constantly hounding the bomb that you are trying to protect. Eliminate the remaining enemies and set off the bomb to open up a giant hole in the floor. At this point, your control will transfer to Jazz as he jumps down into the massive pit, using his grappling hook to make his way safely down where you as Cliffjumper could not. This will lead you into the next level.