Hello RedFox64 and thanks for your compliments.
Sorry for the very late reply, work and private life have become very busy so I can't enjoy spending time on game programming anymore.
Regarding your questions, I manually ripped each frame from the aracade game by running it at original res and saving game session into uncompressed videos, it was so much work!
I have this game running on my arcade cabinet at native resolution, it runs somer smooth, I am so proud of it, will post some video soneer or later :)
The hardest part to make was the timing of each event to make sure it reflected the original game. I literally counted the frames for each action, both the schuedules ones that the random ones.
(i.e. when you complete a level, each step that Donkey Kong does on the latter happens at the exact same timing of the original game, same thing with any score update or even graphic glitches)
Regarding other games, I started with Phoenix but then due to the lact of time I posted here the latest alpha version and never really found the time to go back and continue with it.
In an ideal world if this was my only occupation I could start and complete a remake (plus the extras) in 2 months but unfortunately this is only a passion and work comes first (same for family)
I am pretty sure at some point I will find the time and complete Phoenix, also I'd like to add more levels to DK which is not so complicated to do, so stay tuned.
Both Popeye and Rastan are games I really loved in the '80s but I must admit I loved all them when I was spending time in the arcades ;)