Easy to use and install.
Multiple cursors.
Common keybindings (Ctrl-s, Ctrl-c, Ctrl-v, Ctrl-z, …).
Sane defaults.
Splits and tabs.
Extremely good mouse support.
Cross-platform (it should work on all the platforms Go runs on).
Plugin system (plugins are written in Lua).
Built-in diff gutter.
Simple autocompletion.
Persistent undo.
Automatic linting and error notifications.
Syntax highlighting for over 130 languages.
Color scheme support.
True color support (set the MICRO_TRUECOLOR environment variable to 1 to enable it).
Copy and paste with the system clipboard.
Small and simple.
Easily configurable.
Macros.
Common editor features such as undo/redo, line numbers, Unicode support, soft wrapping, …