Dr. Croid's secret labs were located throughout Magnus and Phonica Moon. They were unlocked when a certain amount of critters were accumulated while playing the game. Completing each of the labs gave the heroes a RYNO VI Protosuit part. There were six Croid labs in total.
- The first of the Croid labs was located in the second segment of Aldaros Plains (Outside Receiving Station) after the heroes escaped the Minion Training Center. It required 12 critters in total. It involved using the Hookshot bungee jumps.
- The second Croid lab was located in the fifth segment of Aldaros Plains (Village Outskirts) around the Lava rock. This lab required 36 Critters. It involves using the Vac-U on the power plungers at the right times to transport a critter through a series of tubes to its destination.
- The third Croid lab was located in the fourth segment of The Deadgrove (Mining Camp). This lab required 48 critters. After you got the objective to "Find the Subterranean Railway Station", walk forward past the armor vendor and co-op launch pad. The lab will be on a lower level.
- The fourth Croid lab was located in the third segment of Octonok Cay (Reef Shallows). This lab required 120 Critters. After the heroes destroyed W.A.S.P. they crossed over a bridge as prompted and onto a raft with 4 Vac-U power plungers. After guiding the raft with your Vac-Us you will come across a black, spikey Tortemoth which you will need to get to move via the Sonic Pylon. After a bit you will see the same Tortemoth, which will go under the thermic mines to your right. Shoot at them with the Combuster and the Secret Lab will be on your left on a rock ledge.
- The fifth Croid lab was located in the third segment on Phonica Moon (Security Tunnels). This lab required 250 Critters. A while after you grab the Reflector you will come to a platform with two laser turrets blocked by glass walls. You will see 4 objects you will need to destroy by redirecting the laser (2 on each side). This puzzle also requires the use of the Vac-U. After this is complete you will see two paths, one going to the left and one going to the right. Take the right path and you will see the fifth secret lab.
- The sixth and final lab was located in the second segment of Uzo City (City). This lab required 280 Critters. After battling your way through a plethora of Minions you will come to a giant Pyro Minion. After you defeat him you will jump up to the room behind him, turn the corner and you will see that you have more lasers to traverse through. This Minion is also on an elevator. After defeating him the elevator will ascend and another battle awaits. After the battle is complete, walk back toward the elevator, go left and you will see the final of Croid's labs.
- Ratchet & Clank: All 4 One (first appearance)