Hell on Earth is more additive expansion than it is revolutionary sequel - Additional weapons and demons bring Doom II to something that feels more complete and rounded out, but doesn't offer much in the way of feeling like a proper sequel to the original Doom.
In broad strokes, the first 20 levels of Hell on Earth's campaign offer a nice upgrade in the intricacy department while maintaining a mostly tight flow throughout that feels like a proper evolution of Doom's level design. The game's final 10 levels, however, sometimes feel like they're trying their very hardest to extinguish any positives of the first two act's offerings, often relying on annoying gimmicks, bloat, and purposeful obtuseness. Extensive gameplay additions like vertical mouselook aiming weren't necessary in the original Doom, but is something that would have been more than welcome given Hell on Earth's insistence on levels with an extreme emphasis on verticality.
Doom II reinforces the idea that though the base game is undoubtedly solid, it's only as good as its levels. Doom II's sandbox is definitive, and was ultimately a venue for commercializing Doom rather than aiming to be a radical follow-up - The sum of those parts: You're probably better off playing through countless user made .WADs using a modern source port.
In broad strokes, the first 20 levels of Hell on Earth's campaign offer a nice upgrade in the intricacy department while maintaining a mostly tight flow throughout that feels like a proper evolution of Doom's level design. The game's final 10 levels, however, sometimes feel like they're trying their very hardest to extinguish any positives of the first two act's offerings, often relying on annoying gimmicks, bloat, and purposeful obtuseness. Extensive gameplay additions like vertical mouselook aiming weren't necessary in the original Doom, but is something that would have been more than welcome given Hell on Earth's insistence on levels with an extreme emphasis on verticality.
Doom II reinforces the idea that though the base game is undoubtedly solid, it's only as good as its levels. Doom II's sandbox is definitive, and was ultimately a venue for commercializing Doom rather than aiming to be a radical follow-up - The sum of those parts: You're probably better off playing through countless user made .WADs using a modern source port.