Crush Depth: U-Boat Simulator

VS

Roblox

Crush Depth: U-Boat Simulator is an indie, niche simulator released in 2021 on itch.io by a small developer. Submarine simulators tend to have a small, dedicated community but are not mainstream. Given its platform and lack of major publisher support, the daily player base is likely quite limited, under 100 players.

Roblox is a massively popular sandbox platform, released in 2006 but continually updated and widely adopted by younger audiences globally. It consistently reports tens of millions of monthly active users, with peak daily actives usually around 5–10% of monthly users. Recent filings and reports indicate Roblox has over 60 million daily active users, but this covers global user logins across many devices and experiences. Adjusting conservatively for reporting and engagement variance, daily actives typically exceed 50 million worldwide, but simultaneous users generally peak in the hundreds of thousands to low millions. As a platform with persistent worlds, it fits the broader MMO definition.