Nope, I’ve never posted, just remember it as a huge trove with a decent vibe.
Pretty sure it is just: create account and post.
I think some people add a CC licence to their works.
This has all the starter info:
https://everything2.com/node/e2node/An Introduction to Everything2
https://everything2.com/title/Everything2+Help
The gridbox shown at the bottom of each page, shows the nodes related to the page you are on.
Some good ones from the fdroid app-repo.
Shattered Pixel Dungeon - already mentioned roguelike
SGT-Puzzles - already mentioned microgame puzzlers
Frozen Bubble - already mentioned bubble-shooter
Vector Pinball - already mentioned pinball
https://f-droid.org/en/packages/net.artificialworlds.boxstacker/index.html - Physics puzzler
https://f-droid.org/packages/com.simondalvai.ball2box/ - flick ball to the box for 3-stars
https://f-droid.org/packages/com.gpl.rpg.AndorsTrail/ - Massive story quest driven RPG
https://f-droid.org/packages/de.chadenas.cpudefense/ - Tower defense on a PCB
https://f-droid.org/packages/ch.logixisland.anuto/ - trad tower-defense
https://f-droid.org/packages/it.alessandropira.wesnoth114/ - hex turn-based fantasy RPG
https://f-droid.org/en/packages/org.lettucepie.flickybee/index.html - flick the bee through the course