The Neo4j Hackathon's Cypher Code-Golf challenge encouraged developers to solve three questions in increasing difficulty levels, with the efficiency of their queries measured by "Database Hits" and query length. Over 5,000 queries were submitted by more than 1,000 participants, and 18 winners received cash prizes. The challenges ranged from finding the maximum number of tags for a question in the Cypher area to identifying the top 10 tags most frequently co-occurring with Lua, requiring users to aggregate data, filter results, and use various techniques like parameterized queries and regular expressions. Despite some issues with invalid queries and lack of capacity to provide explanations, the event provided valuable learnings and a platform for developers to showcase their skills.