Thanks you two!
I kind of assumed it was an aloe but I didn't know they have a pronounced stem. When i got it, it only had leaves on opposite sides of the stem but now it started to grow "rounder".
I'll definitely try to give it more sunlight, I recently moved it from an east-facing window with all-day bright indirect sunlight to a south-west facing window with direct sun in the afternoon / in the evening.
I found a picture of it just after I bought and repotted it, you can see the leaves opposite of each other quite well: