These titles are natively small or can be shrunken to under 50MB when using "Ultra" compression settings in tools like 21 Card Game : A simple card simulation that compresses to approximately Billiard Exciting : Part of various budget series; verified at roughly Billiard Coolshot : A low-asset sports title that clocks in around 10 Pin Champions Alley : A bowling title that fits within the Retro City Rampage

While highly compressed PS2 games may seem like a great option, there are some risks involved:

If you can't find a stable 50MB version, these titles are famously small and stable when compressed: