Throughout the adventure, there are a few bosses that you will need to take down.
Alien Mother
The easiest way to beat her is to use the Blaster, or, if you don't have enough ammo, use the Bomb Glove and run around her. When she attempts to bite, flip out of the way and attack her. Sometimes, she will stay away from you, giving you an opportunity to use the Blaster or restore health.
When the frogs attack, use the Suck Cannon on them and fire them at the boss. Performing a stretch jump will get you our of their range for a short period, during which you can line up a hyper strike. With them all beaten, attack the boss until she calls for more reinforcements.
Finally, when the space lizards attack, kill them with the Blaster or remaining Suck Cannon ammo (or Bomb Glove if they get within biting range), before finishing off the boss with any of the above three weapons.
If you're going for the skill point here, run around the boss until she bites, then quickly jump to her side and hyper strike her. The frogs can be beaten by running away from them, turning, attacking, and contuining to run. The space lizards should be attacked with the hyper strike.
To begin with, you face Drek as Giant Clank. Attack him however you want to, it's not partiularly difficult to beat him here. After that, you can teleport back to your ship and even leave the planet at this point, and itmight be a good thing to. The Devastator and the Blaster should definitely be fully stocked, while the Tesla Claw (if you've got it) should also be. The Visibomb Gun might help, and the Decoy Glove and Drone Device may be of assistance. The Gadgetron PDA can make things easier for you. If you're going to use the R.Y.N.O., you shouldn't need anything else. Follow him when ready.
Drek will attack with barrages of missiles which target the ground before landing, giving you an opporunity to avoid them. He also attacks with homing mines which approach Ratchet if he gets too near. Drek can also launch fire bombs, which explode on contact with the ground and produce a large wave of flame. This can be avoided by jumping over the wave as it approaches you. It also provides a good opportunity to attack Drek, and handily clears the area of mines. After taking a large amount of damage, Drek will fire an energy ball at the area you're standing on, causing it to crack. It will fall away in parts as you move toward the platforms leading to Drek. Follow him and the battle resumes. After more damage, Drek attacks the area again, before retreating to the deck of the Deplanetizer. Follow his mech.
On the Deplanetizer, you will see a cut-scene before the battle continues. Drek has activated the Deplanetizer's countdown, and if you don't use the Thruster-Pack to crash down on it and stop the countdown, you lose. You have thirty seconds at first, and this gradually decreases every time he activates it (which he does several times). Drek has three new attacks. When you deactiovate the countdown, he will chase Ratchet with a heat shield around his mech's engines, which will damage Ratchet if it touches him at all. Run toward the rails on the edge of the Deplanetizer and grind on them (attacking Drek if you've got enough ammo) until he stops. Drek can also deploy several robots which will chase Ratchet - again, grinding on the rails works to help you avoid them, and Drek's bombs will destroy them anyway. Drek's final attack is when he flies away from the Deplanetizer and starts firing energy balls at you. These can be difficult to avoid, and grinding might be of help to you. Eventually, missiles will start flying everywhere. Move constantly to avoid them and keep at Drek until he finally loses.
You take on Qwark in a space fight in the Oltanis Orbit. This is your revenge for him causing you so much trouble throughout the adventure. Stay reletively close to him and keep blasting away at his ship with your machine guns and missiles. Watch out for the mines and rockets he lets loose on you. These can be dodged by shooting them or simply flying away from them. Occasionally he will stop and try and suck you in closer to him while blasting rockets at you. Blast all these rockets and continue on when he flys away. Eventually he will set a bunch of flying minions on you. Destroy them all and continue back on Qwark. After awhile of flying through space trying to catch him, as well as shooting at him as constantly as you can, he will be defeated.
On Planet Umbris, after fighting your way through the Gauntlet to Qwark, you find out that he is working for Drek and has been trying to kill you. He releases a huge Snagglebeat on you that you need to take out to survive. The battlefield looks like a bunch of little islands with attached bridges, lava all around.
Stay a good distance away from it or it will blast you and take out lots of HP. It will send out 3 shockwaves that you need to dodge (or be far enough away from so that they dissolve before reaching you), followed by a laser blast on the ground that will briefly burst into flames (which you also need to dodge). Between the last shockwave and laser blast, you need to run close enough to him to blast away at his health with your Blaster and/or Agents of Doom. Run away when he starts to shockwave you again. Keep repeating this until he gets fed up, rawrs, and then puts up an energy shield and runs after you. When this happens, you need to cross a bridge to another island. He will follow you, but the bridge will collapse and he will fall into the lava and lose HP. The bridge will then be a few little bridge segments floating in the lava, which you can still cross. Do not stay on a piece of bridge debris for too long because it will drop into the lava. He will jump out of the lava and be on a new island.
Repeat the steps of blasting him (as said above, do not go too close) and running to a new island so he follows you over a bridge and it collapses two more times. After the second time, it is very important that you do not go too close to him, or he will send out a tornado breath at you and steal all your weapons ammo, and scatter it around the map (you will then have to take a break and run to collect all your ammo, which is very dangerous because it is very easy to fall into the lava and die). After the 3rd bridge collapse, he will disappear into the lava and be defeated.
You are transformed into Giant Clank and have to fight your way to the circular battle arena in the center of the planet. When there, you fight a giant mech robot with tons of strength and firepower. Throughout the battle, he will attack you with powerful punches. Little flying enemies will shoot at you the entire battle, so take some of them out occasionally because they will be doing most of the damage on your HP. Simply blast away the helicopters with your missiles as much as possible, and attack the Ultra-Mech with your missiles and special, and punch him when possible.
