I think he's talking about what features a 2D engine can do like at the sprite level not at the `type of game` level.
Although I'm writing my own, useful features would be a general particle engine which lets you animate the sprite, move it, scale it, rotate it, change its transparency, add tinting, stretch it, render it warped or in different blend modes, perhaps tiling, more 2d drawing functions, glowing lines, splines, that kind of thing.
Although I'm writing my own, useful features would be a general particle engine which lets you animate the sprite, move it, scale it, rotate it, change its transparency, add tinting, stretch it, render it warped or in different blend modes, perhaps tiling, more 2d drawing functions, glowing lines, splines, that kind of thing.