Wow, two hours... I'm interested, but could you or anyone else give a shorter list of candidates that would be good for the game, or are just interesting?
Maybe this helps, in the description of the video there is this:
Megastructure Index
0:00 - Intro
03:23 - Active Support
04:30 - Alderson Disc
08:30 - Arcology Megatower
09:48 - Arkship
10:49 - Artificial Sun
11:49 - Asteroid Colonies
13:02 - Atlas Pillars
14:19 - Orbital Banks
16:29 - Bernal Sphere
17:34 - Birch Planet
20:48 - Bishop Ring
22:55 - Black Hole Gravity Generator
23:54 - Black Hole Power Generator
25:40 - Bubble Hab
26:36 - Buckyhabs
28:12 - BWC Megastructures
29:08 - Caplan Thruster
29:46 - Carbon Nanotubes
30:31 - Chainworlds
31:07 - Chandelier Cities
31:45 - Clarketech
32:30 - Cube Worlds
33:24 - Cylinder Habitat
36:09 - Dark Sky Station
36:37 - Disc Worlds & Flat Earths
38:01 - Dyson Spheres
40:04 - Dyson Spike
40:45 - Dyson Swarm
42:14 - Ecumenopolis
42:44 - Edersphere/Ederworld
43:52 - Fusion Candle
44:29 - Graphene
44:49 - Record Plating
45:20 - Hammer Hab
45:48 - Helios Drive
46:43 - Hoop World or Donut World
47:27 - Hydroshell
48:13 - Interstellar Black Hole Highway
48:48 - Interstellar Laser Highway
50:06 - Jenkins Swarm
50:27 - Kalpana 1
51:28 - Kipping Terrascope
52:08 - Lagging
52:57 - Lofstrom Loop
53:52 - Magmatter
54:50 - Matryoshka Brain
56:45 - Matryoshka Shellworld
57:53 - McKendree Cylinder
58:36 - Megatelescope Arrays
59:25 - Mini Earth
1:00:30 - Mushroom Habitat
1:01:26 - Neptunian Chainsaw
1:01:55 - Nicoll-Dyson Beam
1:02:52 - New Drive
1:03:16 - O'Neill Cylinder
1:03:57 - Orbital Plates
1:04:42 - Orbital Ring
1:07:22 - Paperclip Maximizer & Gray Goo
1:08:26 - Parabolic Habitat
1:10:08 - Planet Brain / Jupiter Brain
1:10:35 - Planet Ships
1:11:25 - Planet Swarm
1:12:21 - Planetary Cycler/Aldrin Cycler
1:13:10 - Power Beamers
1:13:55 - Quasar drive
1:15:25 - Quasite
1:16:00 - Red Globular Cluster
1:17:14 - Relativistic Kill Missile
1:17:55 - Ribbon Worlds
1:19:12 - Ring Habitat
1:20:06 - Ringworld
1:21:36 - Rotacity or Bowl Hab
1:22:19 - Rungworld
1:23:25 - Shell World
1:24:53 - Shkadov Thrusters
1:25:37 - Sky Cities & Cloud Cities
1:26:38 - Skyhooks
1:27:24 - Smoke Ring
1:28:26 - Solar Mirrors
1:29:21 - Solar Shades
1:30:29 - Planet Sombrero
1:30:51 - Space Elevators
1:32:18 - Space Farms
1:33:27 - Spin Gravity
1:34:05 - Space Towers
1:34:50 - Stanford Torus
1:35:45 - Starlifting
1:36:55 - Statite
1:38:31 - Stellar Pinwheel
1:39:00 - Stellaser
1:40:34 - Suntower
1:41:51 - Supramundane Worlds
1:42:57 - Terran Ring
1:43:58 - Topopolis
1:45:07 - Unobtainium
1:45:35 - Valley House
1:45:55 - World House
1:46:26 - Wormhole
1:53:00 - Credits