Unity Assets

ProtoShape 2D is great asset for making quick 2d levels. I use it for platforms in Rolling Renegade.

Shaper 2d is tool for making procedural 2d shapes. I use it for making procedural spikes and other things in Rolling Renegade.

Flax Fx 2d Effects is a small collection of effects. I use it for the sun rays effect when starting and completing levels in Rolling Renegade.

Shapes 2d is a free tool for making 2d shapes.

Ferr2d Terrain Tool is very good tool similar to Unitys own Spite shape but better for making interestingly shaped levels. If I made a game not abstract I would use this for designing levels.

Shapes  is an asset from Freya Holmér which I don’t own yet because its a little expensive. But it looks fantastic and worth the money. I’ll probably buy it soon.

Geometry Algorithms is an asset which gives you a bunch of tools for produral generation.

I use it mainly to generate concave hulls for procedural platforms.

Strata

Random From Distributions is an amazing free asset which allows you to return a random number from many different probability distributions.