I didn't read any readmes myself I just pressed random buttons until something happened. I think the render speed toggle is either sin or cos, not sure which. It'll give you a message.

Deep THought the controls were in another post before actually. That's where I actually got them

Also I didn't notice that Doom II can be ran too now!

Bug report: Sometimes, black rectangles appear behind the HUD numbers.

Bug report: Sometimes, black rectangles appear behind the HUD numbers.

This appears when you make screen smaller / larger (by [-] / [ + ] buttons). Or is another case ?

I had the same problem. Also I managed to crash the game and it said something about a bad Zmalloc (but I used noclip to go outside the map, so it was pretty legit).

I do not understand. If you use no clip, clipping (by walls) is disabled. Malloc can fail in any case. These 2 are completely independent things.
Zmalloc == malloc on heap owned by doom (= memory management handled by doom)

BTW: bug in this forum, if you remove spaces from string "[ + ]", you get this: "

• "

Is it not the BBCode for a list macro?

Probably, I do not know. I use plain text.
I like the convertor at old casiocalc, where e.g. [F1] was converted to an image of the F1 button of the calculator.

Yeah the black background thing happened when resizing the screen.

Ok. Well personally I didn't see much speed difference anyway when resizing it down slightly, and when too small it's hard to see anything anyway.

In the meantime, could you change the text from white to red like in the original game?