Heretic was always going to be a pretty good game.
This isn't because the original concept was incredibly inspired or the sheer game-making prowess of Raven Software at the time. It's because this is a Doom clone. Not in the sense of it merely resembling Doom's design (like the Build Engine games that originated at around the same time), but in the sense of it being built on Doom's engine and largely feeling incredibly similar to Doom 1 and 2 in terms of game feel and design.
This isn't to say that Raven didn't add things to Doom's design; while most of the weapons have a Doom 1 equivalent, they tend to have slightly different particulars; the Dragon Claw doesn't share ammunition with the wand, the bow shoots 3 arrows, one of which is more powerful than the others, etc.
Unfortunately, most of these changes aren't really for the better. The exception is the complete eradication of "hitscan" enemies, which is on its own probably enough to make Heretic better than Doom 1/2 to some people. The addition of an inventory system also adds a bit of strategy and planning; while a bit janky in execution, I think the idea is solid. But in exchange, you get enemies that have knockback like Simon Belmont and every enemy has several attacks, many of which are unpredictable and difficult to account for in a way Doom rarely was.
The most baffling of these design choices is the decision to apply different rules to boss monsters; several items won't affect them, and other enemies won't infight with them. The infighting gutting would be a bad choice in any game utilizing Doom's mechanics, but it gets unforgivable in episode 4 and 5. where as some sort of bizarre difficulty scaling choice, every level has multiple Iron Liches and at least one Maulotaur, often placed in the most dickish locations possible. I'd argue this is actively worse than the classic Cyberdemon spam, and this is a commercial game!
The level design in general is...it's fine. A lot of the switches are nonsensical and open doors and raise/lower platforms on the complete other side of the map, some levels require usage of a flight powerup that never feels natural, and I generally got lost a hell of a lot more than I did in Doom 2, which I already thought had some inconsistent level design. The first levels of episode 3, 4, and 5 are also exponentially more difficult than any other level in the game; there definitely could've been a bit more attention paid to level balancing.
Heretic isn't a bad game; the game feel is excellent, as to be expected of a game that's basically a glorified Doom WAD, and I did have fun going through the levels, even if I have some complaints with a good chunk of them, but I don't think it's on the level of Id's in-house Doom engine creations, and I'd probably recommend just playing Plutonia or a user-made WAD over it.
This isn't because the original concept was incredibly inspired or the sheer game-making prowess of Raven Software at the time. It's because this is a Doom clone. Not in the sense of it merely resembling Doom's design (like the Build Engine games that originated at around the same time), but in the sense of it being built on Doom's engine and largely feeling incredibly similar to Doom 1 and 2 in terms of game feel and design.
This isn't to say that Raven didn't add things to Doom's design; while most of the weapons have a Doom 1 equivalent, they tend to have slightly different particulars; the Dragon Claw doesn't share ammunition with the wand, the bow shoots 3 arrows, one of which is more powerful than the others, etc.
Unfortunately, most of these changes aren't really for the better. The exception is the complete eradication of "hitscan" enemies, which is on its own probably enough to make Heretic better than Doom 1/2 to some people. The addition of an inventory system also adds a bit of strategy and planning; while a bit janky in execution, I think the idea is solid. But in exchange, you get enemies that have knockback like Simon Belmont and every enemy has several attacks, many of which are unpredictable and difficult to account for in a way Doom rarely was.
The most baffling of these design choices is the decision to apply different rules to boss monsters; several items won't affect them, and other enemies won't infight with them. The infighting gutting would be a bad choice in any game utilizing Doom's mechanics, but it gets unforgivable in episode 4 and 5. where as some sort of bizarre difficulty scaling choice, every level has multiple Iron Liches and at least one Maulotaur, often placed in the most dickish locations possible. I'd argue this is actively worse than the classic Cyberdemon spam, and this is a commercial game!
The level design in general is...it's fine. A lot of the switches are nonsensical and open doors and raise/lower platforms on the complete other side of the map, some levels require usage of a flight powerup that never feels natural, and I generally got lost a hell of a lot more than I did in Doom 2, which I already thought had some inconsistent level design. The first levels of episode 3, 4, and 5 are also exponentially more difficult than any other level in the game; there definitely could've been a bit more attention paid to level balancing.
Heretic isn't a bad game; the game feel is excellent, as to be expected of a game that's basically a glorified Doom WAD, and I did have fun going through the levels, even if I have some complaints with a good chunk of them, but I don't think it's on the level of Id's in-house Doom engine creations, and I'd probably recommend just playing Plutonia or a user-made WAD over it.