The textures…the god damned textures. Especially when mixed with uv mapping.
I’m already crappy enough at uv mapping, can’t seem to understand the basic concept behind the ‘no stretching’ rule, then comes the ‘Crap, need to make a texture for this UV template’, that is when I really start thinking about dropping a project. Yeah…you read correctly, I contemplate dropping a project because I can’t make textures.
That honestly is the worst part of being a crazy indie game dev, I work alone – end of discussion -, so if I don’t know how to do something I either learn how to do it or I just say ‘Fuck it.’ and forget about it.
I learned 3D modelling because of that – no matter how crappy my ability is -, then programming, now looking at how to make music and sound effects. But the damned textures always get the better of me, I read tutorials about textures, books, video tutorials, anything I get my hands on. Final result: Crappy looking, flat textures.
It really makes me frustrated, because no matter how much I study about them and try to make textures I see no progress towards a ‘good’ or even ‘average’ texture. Using 3D modelling as an example – while I’m still a very crappy modeller – every time I start a new model I feel it’s easier and that at least the way I work is getting better – the same can’t be said about the end result – but that doesn’t happen with textures, no matter if I use photographic reference or not, textures end up being crappy. 
Then I mix crappy textures with ‘not even noobs do it like that’ UV maps, which results in texture stretching beyond what people thought as humanly possible.
I guess my next project will be all black and white…