The whole approach to writing games changed when PCs became fast enough to redraw the entire 'scene' every frame, just like a video.
Prior to that, various special techniques had to be adopted to achieve an acceptable speed: hardware scrolling, sprites, palette animation etc. They could make a huge difference to the performance, but were quite limiting. For example hardware scrolling might only be able to scroll the entire screen, so if you wanted to scroll just a portion, it didn't help. Sprites might be limited in their size, and might have only a binary transparency (each pixel entirely transparent or entirely opaque).
Now everything is done differently. At the start of each frame you completely clear the screen and then you draw, from scratch, everything in the scene (generally working from the back towards the front, so foreground objects naturally appear in front of background objects). So long as you can draw everything in one frame period, all the limitations are removed.
All DW's games work this way. I can't see any obvious reason why a platform game should be any more difficult than any other when this approach is used. And although you say DW has never written a platform game before, I would draw your attention to the Treasure Tower sub-game in his prizewinning Maisie Bones submission of a few years ago. That is to all intents and purposes a platform game, in my understanding of the term.
