Pulp was designed for graphics 8 × 8 px in size. If you stick to that scale, things stay nice and simple.
If you’re ok adding code to your game, there are ways to build a sprite out of several tiles. See this post: Pulp how-to: two-tile-tall player
That can get hairy, though, and I’d recommend first seeing what you can do with Pulp’s native tile size. Good luck!