Let's not forget the development of Doom on NeXT, which ironically went on to make PC/DOS cool in gaming:

https://en.wikipedia.org/wiki/Development_of_Doom#Programmin...

It wasn't ironic, at these "earlier" times it was common to use significantly stronger computers to develop for the "smaller targets": in 1975 Altair Basic, the first product of (then called) Micro-Soft, which had to run on the 8080 computer with only 4 kilobytes of memory was developed on the PDP-10 computer owned by Harvard University:

https://en.wikipedia.org/wiki/Altair_BASIC

Paul Allen wrote an emulator for the microprocessor which run on PDP-10. He was able to extend his previous version of emulator for that.

At the time Microsoft developed MS-DOS (actually modifying the program they have bought), around 1981, they owned their own DECSYSTEM-2060:

https://en.wikipedia.org/wiki/DECSYSTEM-20

Also, the original Lucasfilm Commodore 64 games, such as Maniac Mansion, were cross-compiled on UNIX workstations, transferred over the network and uploaded to running C64s — way back in 1987! (Source: The Thimbleweed Park podcasts [0], which I highly recommend.)

[0]: https://blog.thimbleweedpark.com

Three years earlier, the development for the 1984 game "Match Point" for ZX Spectrum (the graphics in the video is original, the sound is fake by the youtube video producer):

https://www.youtube.com/watch?v=eRO_nY-d94w&t=22s

was done by then-just-software company named Psion on their VAX computer:

https://archive.org/stream/sinclair-user-magazine-036/Sincla...

And for developing on the early Macintosh you had to have a Lisa Workstation[1]

[1] http://www.folklore.org/StoryView.py?story=3rd_Party_Develop...