Seeking for spoilerless help
I've managed to get the whole game up until now without using any maps/guides and would like to keep it this way but I want to make sure that I'm not searching in vain
The only things that I haven't found (that I know of) are: 1 key, 1 written tablet thing and 1 purple triangle in the south section.
I also haven't finished the wave mode but I doubt one of these is down there.
I wanted to find these 3 things before activating the thing in the centre (don't tell me what it is, please) and now I'm wondering if at least one of those is after activating that (without any spoilers).
So, is it after activating the center square, or do I need to look harder in the map?
If one of these could be in a particularly hard to find place, if you want, feel free to give me a hint, but without spoilers please :)
Thank you in advance guys!