After the 1.0 update, the game is set by default to get to the final stage, which ends the game. But if you're here, you might wanna know how to keep looping the stages like we did in early access. Here's how.
Loop Stages Guide
Stage 5 - Change the teleporter destination
First of all, you need to reach stage 5.
Once you spawn in the map, you get this message...
...which means that if you activate the teleport, you go into the final stage.
Instead, you have to interact with the side of the teleporter and press E which changes the destination of the teleporter.
Once you interact with it, the teleporter changes form and becomes like this...
...and if you get this message, it means that you get teleported to the 1st stage and you start looping.
Note: Change the destination first, then charge the teleporter!