Trials Fusion

Track: Winter Getaway
Bike: Pit Viper or Roach

Continue to the 2nd checkpoint where you will end up in front of a ramp, with a building behind you. You'll need to go up this ramp, and bail on top of this building inside of the left hand side vent. Once you land inside, it will start a Trials 2D mini-game. Just complete this level to unlock the achievement.

My YouTube video below explains/shows you in less than a minute! This achievement is quite easy and shouldn't take you too long. Just get to the second checkpoint. Bail into opening on top of the apartment. Complete the arcade game!

As it says this achievement is obtainable on winter getaway, you'll want to start the track and get to the 2nd checkpoint and stop there. Once there you'll see a big window right above the checkpoint to the right, this window has 2 armchairs and a tv in there. Now your going to want to drive straight up the steep ramp (the very next obstacle) and bail out at the top trying to get as high as you can and then push up on the left stick to steer your dude into the hole above the tv and armchairs , once you land inside it will automatically start the little mini game you need to complete not hard at all upon completion achievement unlocked. Hope this helped

Bike: Pit Viper
Track: Winter Getaway

Load up the track 'Winter Getaway' and get to the second checkpoint. In front of you there will be a steep ramp, as you hit the top of the ramp press 'Y' and hold 'up' and the left stick to bail upwards. Once bailed aim for the open vent on the roof and fall through it. A mini-game will appear on a computer screen called 'Super Trials' you must complete this track in order for the achievement to unlock. You may fault whilst completing the circuit.

The achievement will unlock as soon as you pass the finish line.

Pretty much just a follow up for the above two guides. Exact same thing. Arrive at the second checkpoint, and bail out as high as you can, then pushing your Rider inside the roof opening. Once inside you will land down onto the chair, and the camera will switch to the Television inside. The mini game will then start.

I did some trial and error for this achievement, and from what I can see if, when you are inside the mini game, you can not have any faults. I completed this mini game on a few different accounts, each trying different ways around it.

Completing the mini game with deaths before the game, and deaths inside. No achievement.
Completing the mini game with deaths before the game, and no deaths inside. Achievement popped.
Completing the mini game with no deaths before the game, and no deaths inside. Achievement popped.

Hopefully that will give you a hand. As the other guides said nothing about deaths, nor does the Achievement. But I saw people asking in the comment section saying what was going on, as they have completed it, but still no Achievement.