Never played the Quake 1 Mission Packs before, so as a little tangent to all the Doomin' I've been doin' I decided to finally see what they're all about.
Here's my playthrough time tally with my Quake playthrough time as a reference, all of them played on hard.
The packs were made by different developers (Hipnotic and Rogue) and they both have their own styling and additions to them. Armagon was a bit more impressive with the visuals, shotgun blasts would leave markings on walls, you'd have more unique visual aspects to the levels like an energy bridge, just things like that. In terms of new weapons you had a proximity mine launcher, which acted as an alternate grenade launcher that ended up being mostly useless; laying traps for enemies to walk into just isn't in the scope of Quake combat. You also get an automatic laser rifle, close to the ones the laser guards use; looks like three rocket launchers taped together but was the most useful of the new weapons and a pretty worthy inclusion to the arsenal. Last weapon you get is Mjolnir, Thor's hammer itself; as cool as this sounds it's not very worthwhile in practice and I'd rather use my cells for the LG or the aforementioned laser rifle -- dunno how you'd go about reloading a hammer either. The new enemies mostly suck, unfortunately. You have scorpions with nail guns for claws, which is admittedly a great concept, but not very fun to fight. You have large airborne mines that home in and track you, which you can only seem to combat indirectly by making them hit a wall -- they use a lot of these throughout and are incredibly annoying. I do like the gremlins though, which are kind of look like miniature fiends, but instead of lunging towards you they steal your weapons and try to run. They added a new item, the horn of conjuring, which spawned a (random?) enemy type as an ally, which you could identify with their emitting glow. Pretty cool to have a shambler on your side I gotta say. Level design was nothing really special though and enemy placement was kind of scattershot. They loved plopping shamblers wherever they felt like it.
Dissolution took a different approach with weapons, instead of adding anything completely new it added alt ammo for a bunch of the existing weapons. With nail guns you can find, get this,
lava nails, and they don't end up changing things radically. They do more damage, they have a different sound effect, woo. Grenade and rocket launcher get multi-grenades and multi-rockets, the lightning gun gets a plasma ball the spits out chain lightning. The added enemies are mostly fine, being variants or reskins of existing types, but the one really different one that gets sprinkled about most really sucked. Flying wraths that do the homing projectile shtick for attacks, seems to be the popular choice between the two different developers and they were both butts. We already had the revenant-like in Quake, can we please just leave it at that. There were also some flying swords which were notable in how lame they were to fight. Again, level design wasn't all too special and the amount of ammo you get is excessive, I was almost using rockets and multi-rockets exclusively. Neat thing about both mission packs is that they both have cutscenes; they're simple and crude, but actual cutscenes. Boss fights in both were pretty dull, but that was kind of the norm for the time, the one in Armagon (well, Armagon himself) felt reminiscent of the final Q2 boss.
I mean, they were more Quake to play but I'm not really regretting having not played them sooner. Still, they were fun and being as short as they were never started feeling like they were stretching thin. I'll have to give the Q2 expansions a whirl eventually.