The "look" of games changed drastically. This was the era where (the precursor to modern game security) started becoming mandatory for featured games to prevent hacking. While it made scripting more difficult initially, it forced a professionalization of the coding standards within the community.
For scripters, 2015 was the year of . This allowed Roblox games to communicate with external websites, enabling things like global leaderboards, external databases, and Discord integrations. It transformed Roblox from a closed sandbox into a platform that could interact with the wider internet. Community & Aesthetics Roblox Studio 2015
2015 introduced several technical milestones that expanded the scope of what was possible on the platform: The "look" of games changed drastically