The box copy comes with a 2 CD jewel case with the Megawad plus original music by Metal God Buckethead. For original Doom fans the Megawad seems like a must play and for avid PC game collectors this Limited Run pressing seems just as important. Please believe I'll be playing the Megawad on launch and I'm still deciding if i'll be picking up a physical release.
"SIGIL is a free megawad for the original 1993 DOOM created by John Romero. It contains nine single-player and nine deathmatch levels. The free megawad will be released in mid- February 2019 and requires players own the original 1993 registered version of DOOM in order to play. SIGIL is the spiritual successor to the fourth episode of DOOM, and picks up where the original left off.
You can play SIGIL with several modern source ports such as GZDOOM, or the Steam version of DOOM. You must own the original registered DOOM or The Ultimate DOOM to play. SIGIL is playable in Co-operative, Deathmatch, and Single-Player modes. SIGIL is for PC/Mac."