https://book.leveldesignbook.com/ good book on level design
https://tetr.io/ tetris
https://lichess.org/ best chess site
http://www.studyopenings.com/ study your opening
https://noclip.website browse game maps
https://devdocs.io/ programming language docs
https://orbital-market.com/ 3rd party UE marketplace browser
https://trianglify.io/ random patterns
https://r.3v.fi/discord-timestamps/ timestamps in discord messages
https://bysam.github.io/strafe/#x1-40003 notes of improving fps strafing
https://martinfowler.com/bliki/FrequencyReducesDifficulty.html frequency article
https://www.eloshapes.com/ compare mouse shapes