Didn't get Sequence Breaker achievement - never found Jetpack (end game spoilers)

[Gold♥Shield]

I made it to the end of the lava temple without ever getting the jetpack but I didn't enter the final area because I thought it was the final part of the game, so I went back and started mining out the rest of the areas only to find the other devices of destruction. I destroyed them all - never once finding the jetpack, but I beat the game and didn't get the achievement.

Mind you I wasn't trying to get the achievement. I just found myself at the end of the game and wondered what I missed and saw mention of using the jetpack to access the later stages of the lava temple.

Any ideas?

[Hiroshi Mishima]

Well, did you do Vectron? Cause that's what it really means by sequence breaking. You can actually skip the Jetpack entirely even though you did Vectron, insofar as I can tell. But if you did Vectron you are out that achievement this time through.

[Gold♥Shield]

I didn't ever do Vectron but I just figured it out after starting a new game. The very first doomsday device you encounter in the temple I completely skipped on my first playthrough. I don't even know how I skipped it, but since I always check for secrets before continuing on, I found the treasure room and got the long-range grapple and my mind immediately went to "Hey, I bet I can cross that lava lake now" and I completely forgot about the cave five feet away from the treasure room.

Loaded up my old save and sure enough, I didn't even have that part of the map explored, so I went in and destroyed it (which gave me the achievement). I then got the quest objective to go speak to Rosie about stopping the quakes, but since I already had confronted Rosie at the very end of the game, my quest objective updated from Speak to Rosie to Confront Rosie.

So I guess you can skip the entire first Doomsday device and still beat the game. That first one is just a quest trigger to tell you to speak to Rosie who then apparently tells you to go to Vectron. Since I never hit that trigger, my game didn't know what to do and it just told me to keep smashing Doomsday Devices until I got the last one from just exploring and I beat the game without getting the achievement.