A huge "behind-the-scenes" issue with my demo was the dialogue system. It worked but it was a mess. 7-8 lines of dialogue would take around 15-20 minutes to implement with around 30 events (Construct 2's "lines" of code). This increased the possibility of errors and it was just an unwieldy beast. The dialogue and the story is the main driving force in my game, so it needs to be easy to use, able to handle a lot of dialogue, and quickly editable.
I purchased a dialogue template via the Scirra store and spent most of last week and Saturday struggling to get it to work. After a lot of hair-pulling and help from the creator, I got it working last night!
I made this gif and directed it at the creator. A quick-to-respond and helpful person!
It is a super slick system that references an external file, so I'm not writing all of my dialogue in the engine. I need to edit the dialog box, add portraits, and tweak the "continue" button, but it already looks much better than my previous dialogue system!