There are a bunch more, but superhires is probably the only useful one anymore.
From the retail version's readme.txt:
-Verbose Shows initialization steps for tech support
-LowMem Lower animation detail for better performance with low memory
-NoLowMem Force high animation detail even when low memory
-NoMemCheck Disables memory requirement checking
-NoDOSCheck Disables DOS version checking
-NoFileCheck Disables the file handles check
-NoHighRes Disables 640x480 mode for menus and movies
-ForceVesa Enables VESA linear frame buffering (if available)
-Subtitles Turn on movie subtitles (English-only)
Input devices:
-NoMouse Disables mouse drivers
-NoJoystick Disables joystick support
-JoyPolled Poll joystick w/ counter. Use for Windows, OS/2
-JoyBios Use the system BIOS for joystick.
-JoyNice Joystick poller allows interrupts to occur
-GamePort Use Colorado Spectrum's Notebook Gameport
Sound & Music:
-Volume <v> Sets sound volume to v, where v is between 0 and 100
-NoSound Turns off sound & music
-NoMusic Disables music; sound effects remain enabled
-DisableSound Completely disable sound system (also disables movies)
-NoLoadPats Disables patch loading for Gravis UltraSound
-Sound22K Use 22KHz sounds, even if machine has less than 16 MB
-Sound11K Use 11KHz sounds, even if machine has more than 16 MB
-No16Bit Disable 16-bit sound (movies only)
Network & Modem:
-CtsRts Enables CTS/RTS handshaking during null-modem games
-NoNetwork Disables network drivers
-NoSerial Disables serial drivers
-Packets # Specifies the packets per second where # is the number
of packets
-Shortpackets Turn on short packets
-Norankings Disable multiplayer ranking system
-Noredunancy Suppresses duplicate messages such as "You already have ..."