I've restarted again. I really gotta stop doing that someday! ;)
It's some kind of silly Metroidvania project.
I've just finished working on the map system,
although I have no idea what causes a whole line to be skipped on the map, as seen at the end of the video. Hopefully it's some kind of bug on Construct 3's end, otherwise I don't know where to start xD
Edit : I found the solution. I had been an idiot and had forgotten to compensate for something. Works like a charm now. One less headache in my way x)
Some concept art thingamajig :