This was a small game; the Dutch of course slowed me down, but the text was generally simple and repetitive, and I only had to look things up on words like “traangasgranaat” (tear gas grenade).
(Just to keep the eyes on the prize in what follows: the goal is to get at a treasure. The treasure turns out to be hiding in the Church of St. Steven in Nijmegen.)
Where I really had trouble was getting in the same frame of thinking as the protagonist: make progress by any means necessary, including violent property damage. The tear gas should have been my first clue, and I later found a weapons shop selling a “thermischelans geweer raket” (“thermal bazooka”, I think?) but as Nijmegen is described as a “real city” my first tendency was to play in those terms. This stymies most early progress; while it is possible to get most of the starting map without solving any puzzles…

Reminder note: there are no compass directions, you move by typing GA (“go”) followed by the name of an adjacent location; for example, GA GROTE MARKT, “go great market”.
…one early thing you need to make much progress is to smash the parking meter in the first location and grab the money (>FORCEER PARKEERMETER — I don’t think “FORCE” is a verb I’ve ever seen in an English game, would it be easier to find playing in Dutch?) The money from within lets you visit the nearby Fotozaak (photography shop) to get some binoculars and the Shoenwinkel (shoe shop) to get some boots (that must have been a lot of change).
The other open place is a “tower” (you need a “latch” from nearby before you can go in) which has a basement with the hint “look in the distance”.
Climbing the tower lets you get up to a room you can use your binoculars and see the message “DRINK MEER BIER” which is a key phrase. Use it back in the basement to find a secret room and get yourself some dynamite.
You can use the dynamite to explode a building at a quay and get some gin, which seems a fair tradeoff for the property damage; the gin can be used to bribe your way into a new location with a crowbar. You can then use the crowbar to move a rock to get some keys, which let you break into the church (making sure you throw your tear gas grenade first).
Inside the church there is a “duck shaped” opening; you can use boots to reach high enough and use a duck from the park which opens a safe, finally yielding the treasure.

You’re rich, you managed to get the gold, are you very smart or very bad? (I’m not sure on the last two sentences, but it’s something like “now, go waste your money”.)
This was really odd and random to play; unlike Dracula which had layers of narrative, this was intended as a random path of adventurer destruction, where destroying an entire building to get some gin is a perfectly acceptable exchange. At least the game was self-aware about it.
…
Some quotes from here indicate that Wim Couwenberg himself made the original C64 port, and it is identical to the PET version, so there’s no need to go on a grand crusade to find the original (…unlike Dracula Avontuur, where I’m still curious). He doesn’t know who D.N.T is.
He also mentions his brother Jan made the story, so I’ll toss him in my credits. (I really am curious what the writing process for the story was like, since it comes off as a string of random puzzles.)
I apologize I couldn’t do any deep exploration of language learning this time around; most of the parts were all-or-nothing scenarios, where either I easily sussed out what was going on and what the right action is, or I had no idea and even when I did have an idea I didn’t know how to communicate it (for example, blowing up the dynamite is given by the walkthrough as BLAAS OP, “blow up”).
One last item of importance: while perhaps this game isn’t a candidate, the Hans Courbois predecessors (which I still have yet to find, but I’m working on it) might be vying for the title of “first graphical adventure where information is conveyed in the graphics” along with Mystery House; you have to, of course, have a loose definition of “graphics” which allows character graphics, but it’s still a noteworthy convergence, and one I don’t believe any texts in English on adventure game history have previously noted.
I really have to commend you on your effort here and persistence. Not even a little thing like a language barrier is going to slow you down here. Bravo
“finally yielding the treasure”
Hilariously, given the Dutchness of the game, when I saw the illustration of the treasure before reading the caption, I thought they were a pair of glistening clog shoes!
So, you were typing down the dutch words in a translator app all the time, or did you use the phone camera auto translate of google translate?
I like those graphics.
Typing, although I often had to check more than one source.
Agreed on the graphics (and they helped with the translation some).