I love level editors. Every game (where it makes sense) should have a level editor and possibly a randomizer / roguelike mode. I wish someone did a simple level editor for Wave Race 64, just to place the buoy (not sure if that is the right word BTW).

I have seen level editors for Adventures of Lolo games. One example is for 3: https://www.romhacking.net/utilities/759/ The Syphen Filter games would definitely profit a lot from such enhancements, generally speaking the 32-bit and N64 era of gaming.