[IronicDeadBird]

Biggest obstacle hands down for me is waiting for information.
When you are designing for a static game it is really easy to come up with a game plan and run it when the rules don't change like in Chess you can try an opening against a bunch of different openings because the rules are static. Fortunately (or unfortunately depending upon my temper) FRC games are fluid and dynamic and the rules change. Once that happens then the game mechanics change, then designs and strategies for games need to be re analyzed. So the biggest obstacle for me when trying to design something is the resource and information gathering aspect.
Maximum respect to the GDC for having a Q&A system, and for keeping regular updates but the fact that what is viable day 1 and what is viable day 21 can vastly differ throws a major wrench in the works. The biggest time sink I had this year was when the game first came out I was like "lol Ill just drop anchors into the step bins and pull them all into the auto zone for resource denial and multiple bin sets points." It was a simple really powerful opening to a match and it would dictate a lot of design rules. But I had to wait for the Q&A because I needed to know if multiple bin sets could exist. When the Q&A went live they said "yeah no, one set" and also someone caught the technicality I found where the landfill zone was an area and the GDC made it into a volume and I was really sad...

TLR The games tendency to change is the biggest obstacle