@stefan-laimer My exact strategy was setting the level boundaries, a start and finish point and a sequence I found interesting. Then I first made the level beatable with the sequence using environment tiles (such as portals, walls, inverters and reversers) and subsequently filling pretty much the rest of the map with enemies in such a way that few other solutions are possible, however our solution still works. The upside is that designing the levels is a pretty fast process, the downside being that it requires extensive playtesting to figure out which levels are actually hard (because of few other solutions or the solution being unintuitive). This is why I released hints for certain levels which we considered harder than the others. You have my twitter, feel free to message me if you have any more questions :-)