@shavecat
editing the es_systems.cfg to remove ".iso" from the amiga console is one way. Below the <system>amiga</system> tags.
/etc/emulationstation/es_system.cfg
override at >
/opt/retropie/configs/all/es_systems.cfg

Changing the file name to a unix hidden file, then reflecting the changes in the all of .cue/.whd/.conf/gamelist.xml
./.Syndicate (1995)(PAL)(Track1)[!].iso

Or for the hidden tag to function in emulationstation. Kiosk or Kids mode must be enabled. I think:
ES Menu > System (or UI?) > gamelist mode (or ???) > Enable Kiosk mode.
↑ ↑ ↓ ↓ ← → ← → B A to exit kiosk mode.