C21: Steel Battle Chronicles

VS

FiveM

C21: Steel Battle Chronicles is an online action RPG from CyberStep released in 2006. Given its age (over 15 years), niche publisher, and the lack of widespread recognition outside of Japan, it is likely to have a very small but dedicated player base. Its live services seem primarily targeted at a Japanese audience. Unless supported by recent re-releases or major updates, games of this profile generally retain a few hundred to a few thousand daily players.

FiveM, released in 2016, is a popular modification framework for Grand Theft Auto V that enables custom multiplayer servers, especially for roleplay communities. Its active modding scene and the enduring popularity of GTA V have kept its playerbase strong, typically with hundreds of thousands of daily players. However, it's technically not an MMO as individual servers usually host dozens to a few hundred players, not a persistent shared world for thousands.