Imuri was invented independently by Klaus Munro, who later became a famous writer and composer, and in so doing became less interested in defending whatever rights he may have had to the game. The grid is 30x30, which would be significantly deeper than Randolph's 24x24, but the production quality was much better for Twixt.
There are more different editions of Imuri (to be submitted by owners)
different box size: see http://luding.org/Skripte/GameData.py/DEgameid/19694
English subtitles: https://boardgamegeek.com/image/197158/twixt
This one has a red or blue plastic inlay
red one: https://boardgamegeek.com/image/4324637/twixt
Inside of the box: Dutch rules, too. German rules only separately with no. in lower left side: rp 1.039 - 10 000/272
On the sides logo yellow r and blue p with rhön-plastik schipper KG
The 2 plastic boxes with 2 compartments containing the pieces apparently don't come always with the game.
The tape holding the 4 board parts together is often not functional anymore after more than 40 years.