Level design

• The Level Design Book
• Awesome Level Design
• The Fastest Way To Design Levels in Unity 6? Pro Builder Explained
• Beginner Course Level Design - free course from TimDoesLevelDesign
• noclip.website - fly around real game levels, super fun and useful
• How I Make Levels As A Professional Level Designer For Indie Games
• Level Design Approaches for Solo Devs by Indie Game Clinic
• Moving Mountains: Speedy Level Creation as a Desperate Indie Dev

Spline-constrained movement #

• Haunted PS1 Summer of Shivers Jam and the release postmortems: Part 1, Part 2
• True 2.5D in Unity3D Prototype
• Move along a spline in UE5
• UE4 spline-constrained platformer tutorial series
• Blueprint Spline-locked sidescroller tutorial on UE forums
• DannSB's spline-directed platformer prototype on Reddit
• 2.5D platformer implementation discussion one of the commenters shares the problem of variable speed. TL;DR: arc-length reparameterization and no Y axis on the spline can solve some of the problems.
• Movement along a curve with constant speed – blog post.
• Moving along a curve with a specified speed

Shortcomings of Unity's native splines #

• Inconsistent local vs world space method signatures. For example, GetPointAtLinearDistance operates in local space, and the distance it returns will also be in local space -> your spline transform's scale affects the result, i.e. if a spline is 30x scaled, the speed of movement along the spline will be 30x faster.