I know a challenge: TheDRAW

[TempodiBasic]

here you can see that it had been built with TurboPascal and Assembly languages... so it is not too hard  trying to build it by QB64!

Have to get around the assembly parts to make it compatible with MacOS and Linux as well as Windows. Also the one struggling with certain structures in Pascal (linked lists for data, and otherwise OOP) would not interested in porting it to QB64(PE).

So your goal is NOT to build it in QB64, but to translate it in QB64! This last option is too hard!
The assembly parts surely were a must in DOS era, not today in Windows era ... I dunno.

Pascal is not a poor language, TurboPascal  is more powerful, but QB64 is not simply a QB for 64bit OSes...
I think that QB64 is very powerful also though it is a procedural language that have no OOP inside while TP 5.5 and over work also with objects.

Here there are more QB64 coders that play every days with Linked List and pointers... they can give you some essays...
it is a pity that I don't find the link to a thread of some time ago, in which there were 2 o more coders playing with graphic editor o viewer.
They posted a little demo trying to manage the zoom tool... and I remember a very beatyful post of Steve (our SMcNeill) that showed how simple it can be done with pointers.

Indeed to build from zero  TheDraw I think that it needs to have a map of features and items used in it. Just to let think how they can be done in QB64.