Fun maps overall, I especially liked the constant usage of map hacks for rotating and animating props galore, most notably the flags in the Orient level, all the ceiling fans in the resort, the eye-in-the-sky and the clock in Scarabrus, and the drills in the walls at the start of Blastocyst which I thought was friggin' neat as hell. Never felt especially easy or too difficult playing through on Hard, didn't find all the secrets so I might've gotten an explosive weapon a bit late (had 100 rockets by the time I finally got the GL and oh how nice it felt). Did have trouble with finding the multiple-key doors a few times, and was slightly disappointed to find that most of the map size was empty and/or out-of-bounds and was only there for appearance.
Found a number of ways to either get stuck or finish maps early, so spoilers ahead. Namely: first map, if you jump into the beach bar where the Enforcers are you can easily get completely stuck and have to noclip out. In Sun, you can jump off the bridge onto the roof lip, run along to the edge, and if you're good with air strafing, steer yourself around the pillars, then jump to the spiral tower, climb it and finish the level,
hastily scribbled over the tally screen here. Scarabrus allows tricky players to grenade jump over the triple-keyed gate (found the silver and gold keys, couldn't figure out how to make the third cage lift up. probably missed something super obvious.), and you can bypass the entirety of Tattered by jumping onto a few roofs at the level start, then looping around behind the spawn point and jumping the fence at the end. I made a demo of it
here (the demo file is upwards of 12mb for some reason- due to map size?).