Log::Minimal's slogan is "minimal but customizable". It's minimal alright, probably only suitable for simple scripts as the moment you organize your application/library into separate modules, you'll want/need categories instead of just level, which is not provided by Log::Minimal.
Also, only formats is customizable, there is currently no way to customize level. And the levels are "not standard" (not that there is an official authoritative standard, but the popular convention is TRACE/DEBUG/INFO/WARN/ERROR/FATAL and NONE). Log::Minimal's levels are
DEBUG/INFO/WARN/CRITICAL and NONE). Surely most people would expect another level between WARN and CRITICAL, for non-critical errors? But that is actually just a matter of taste.