Chariot

Many of the levels in Chariot have more than one exit; you can see the number of exits on the level map in the topside hub. Each exit, whether it's the main exit or an alternate one, unlocks an entrance in another level. To get this achievement you'll basically need to get to every exit in the game. Some of the exits are "secret" and can be found by exploring hidden areas of the map; other exits can be reached via alternate entrances and the flow of the level leads naturally to them. You'll also need to find 72 skulls to unlock this achievement, as the exit to the secret level is behind a gate requiring them.

Some of the exits require tricky platforming to get to. I recommend using the Attractor gadget as soon as possible, or failing that, the Peg.

Here's a full path of the levels you'll play in a playthrough of Chariot. I've bolded the alternate exits. Note, I didn't consider exits where you find a sepulcher to be alternate exits, since they're part of the story. Level plays in italics do not unlock a new entrance.

Level 1-1: Entrance A -> Exit A. Unlocks 1-2:A
Level 1-2: Entrance A -> Exit A. Unlocks 1-3:A
Level 1-3: Entrance A -> Exit A. Unlocks 1-4:A
Level 1-4: Entrance A -> Exit A. Unlocks 1-5:A
Level 1-5: Entrance A -> Exit A. Unlocks 1-2:B
Level 1-2: Entrance B -> Exit B. Unlocks 2-1:A (Royal Lantern upgrade required.)

Level 2-1: Entrance A -> Exit A. Unlocks 2-2:A
Level 2-2: Entrance A -> Exit A. Unlocks 2-3:A
Level 2-3: Entrance A -> Exit A. Unlocks 2-4:A
Level 2-4: Entrance A -> Exit A. Unlocks 2-5:A
Level 2-4: Entrance A -> Exit B. Unlocks 2-2:B
Level 2-2: Entrance B -> Exit A.
Level 2-5: Entrance A -> Exit A. Unlocks 2-3:B
Level 2-3: Entrance B -> Exit B. Unlocks 3-1:A (Winter Wheels upgrade required.)

Level 3-1: Entrance A -> Exit A. Unlocks 3-2:A
Level 3-2: Entrance A -> Exit A. Unlocks 3-3:A
Level 3-2: Entrance A -> Exit B. Unlocks 2-3:C
Level 2-3: Entrance C -> Exit A.
Level 3-3: Entrance A -> Exit A. Unlocks 3-1:B
Level 3-3: Entrance A -> Exit B. Unlocks 2-5:B
Level 2-5: Entrance B -> Exit B. Unlocks 2-1:B
Level 2-1: Entrance B -> Exit A.
Level 3-1: Entrance B -> Exit B. Unlocks 3-4:A
Level 3-4: Entrance A -> Exit A. Unlocks 3-5:A
Level 3-4: Entrance A -> Exit B. Unlocks 1-5:B
Level 1-5: Entrance B -> Exit A.
Level 3-5: Entrance A -> Exit A. Unlocks 3-1:C
Level 3-1: Entrance C -> Exit C. Unlocks 4-1:A (Dragon Plating upgrade required.)

Level 4-1: Entrance A -> Exit A. Unlocks 4-2:A
Level 4-1: Entrance A -> Exit B. Unlocks 3-5:B
Level 3-5: Entrance B -> Exit A.
Level 4-2: Entrance A -> Exit A. Unlocks 4-3:A
Level 4-3: Entrance A -> Exit A. Unlocks 4-4:A
Level 4-3: Entrance A -> Exit B. Unlocks 3-3:B
Level 3-3: Entrance B -> Exit A.
Level 4-4: Entrance A -> Exit A. Unlocks 4-5:A
Level 4-5: Entrance A -> Exit A. Unlocks 4-3:B
Level 4-5: Entrance A -> Exit B. Unlocks 4-4:B
Level 4-4: Entrance B -> Exit B. Unlocks 4-2:B
Level 4-2: Entrance B -> Exit A.
Level 4-3: Entrance B -> Exit C. Unlocks 5-1:A (Power Core upgrade required.)

Level 5-1: Entrance A -> Exit A. Unlocks 5-2:A
Level 5-1: Entrance A -> Exit B. Unlocks 3-2:B
Level 3-2: Entrance B -> Exit A.
Level 5-2: Entrance A -> Exit A. Unlocks 5-3:A
Level 5-2: Entrance A -> Exit B. Unlocks 4-3:C
Level 4-3: Entrance C -> Exit A.
Level 5-3: Entrance A -> Exit A. Unlocks 5-4:A
Level 5-4: Entrance A -> Exit A. Unlocks 5-2:B
Level 5-4: Entrance A -> Exit B. Unlocks 2-5:C
Level 5-2: Entrance B -> Exit C. End of Story. (Regal Diamonds upgrade required.)

Level 2-5: Entrance C -> Exit C. Unlocks 5-5:A; you will get the achievement here.

Level 5-5: Entrance A -> Exit A. Congratulations!

To unlock this achievement you will need to find all the alternate exits which are located throughout many different levels in the game. There are 19 alternate exits to be found.

You can check if a level has an alternate exit by clicking on the level and looking on the bottom left of the screen, at the picture of a door with a red arrow, under the skulls and blueprints. If it says 1/1 or 0/1, then the level doesn't have an alternate exit.

Each alternate exit you find will unlock an alternate entrance for another level. Just follow the dotted line on the map and it will point to the level with the new entrance.

The levels with only 1 alternate exit are : 1-2, 2-3, 2-4, 3-2, 3-3, 3-4, 4-1, 4-4, 4-5, 5-1 and 5-4.

The levels with 2 alternate exits are: 2-5, 3-1, 4-3 and 5-2.

For 1 of the alternate exits on 2-5, you will need to have found all 72 skulls. This will unlock the hidden level, 5-5.

Note: Not all alternate exits are available by simply following the level. Sometimes you need to unlock an alternate exit on a different level first, which will unlock a new entrance on another level that then leads to the alternate exit (For example, you need the alternate exit on 4-5 to be able to get the alternate exit on 4-4 using the new entrance).

Any questions? Feel free to comment or PM me.