Man, if only the authors had finished this it would be remembered as a true classic of its time.
There’s so much potential here that just never got realised so I won’t go in to the level design or presentation, but two things stand out for me, looking back at this through my 2021 spectacles:
The new base skins are so much nicer than those in successful mods like AD, Quoth and Alkaline all of which utterly gamify themselves by dressing different soldier types in bright Mario colours. They could all learn from the subtler hues and skin alterations used in this mod.
In the final map, there’s actually a useful Ring of Shadows secret, that meaningfully allows the player to avoid combat. Still no good for anybody looking for that sweet 100% kill count, but it’s refreshing to come across.
Mine must be broken because I can only finish the final 2 maps by trick jumping after getting keys that seem to have no doors. It’s a shame because this was pretty good.
Good tech base map, nice visuals, decent gameplay. The beginning might be somewhat overwhelming, as there are enemies everywhere. Relies a bit too much on the "enemies are placed in every nook and cranny" trope, but it's entertaining.
ih1m1.bsp - Link to Nightmare 100% walkthrough: https://youtu.be/ZuTaR5QcjNo
Good metal themed map, with low ammo in the initial area. Looks good, very linear. Gameplay is nice, lots of fights in close quarters. Extra fun if you just keep moving.
ih1m2.bsp - Link to Nightmare 100% walkthrough: https://youtu.be/tHtv2ghUhJg
Different theme, similar type of gameplay. Crowded, low ammo start, gets better after.
ih1m3.bsp - Link to Nightmare 100% walkthrough: https://youtu.be/IW63HjCsWh4
Yet another map, in the style of Episode 4. Some of the Shambler placements feel a tad cheap.
ih1m4.bsp - Link to Nightmare 100% walkthrough: https://youtu.be/keqKMUor-fM
Overall, a good, solid, set of maps that will provide you with a pleasant Quake experience. The maps look good, have nice geometry and each one of them follows a different theme. The custom enemies are a nice addition to gameplay variety, specially in the first map. If Shotgun starting, the initial sections are all pretty frantic, with multiple enemies and not a lot of ammo. Regardless, there is plenty of action in all of them.
There is some over reliance on placing enemies in every corner, trying to surprise you. That gets a bit predictable, particularly in the first map. Like mentioned in previous comments, the latter maps also suffer from enemies spawning behind you. Gets annoying, but it's not terrible.
A shame that it wasn't finished.