Re-worked version of Eggman's 5 levels to be clear-able by the 5 other main playable characters, 2P characters not tested so cannot guarantee. Simply got things in a working state, not well polished (yet).
Use either of the following to allow character selection:
Character Select PLUS: https://gamebanana.com/guis/35023 by Justin113D
Character Select MOD: https://gamebanana.com/gamefiles/6301 by MainMemory (tested with)
Egg Gate: Doors removed including final rocket section (as if you went too far and got stuck in-between doors would soft-lock game) and next to no other edits, many surfaces are climbable, no known issues.
Sand Ocean: WARNING crashes game if you die in the sand as a non-mech, also many invisible home-attack objects which you may find yourself snapping to. Launching speed panel removed due to crashing game with speed characters. Removed rocket container tank things and added platforms to make level traversal possible, somewhat playable but rough with known crashes.
Lost Colony: Removed doors, explosives remain as targets can cause minor issues with homing attack, elevator works but you can't do anything if not a mech, no known issues.
Weapons Bed: Removed doors and no other edits, works completely fine but a little on the difficult side with enemy placement at times.
Cosmic Wall: Substantial re-work with multiple added platforms, springs and items (crushers, pick-ups & balloons) to allow progression. Green/orange spinning targets removed due to issues with the homing attack and causing non-mech characters to 'boop' off of them with slow recovery times, 1 pyramid removed, they are breakable but only with specific attacks (e.g. spin dash). Camera isn't always friendly and 2 auto-tracks 'work' but can't do anything as non-mech character. Works but rough patches and some content missing.
Most surfaces of objects are climbable which can actually make some things fidgety, background structures are typically not climbable in Cosmic Wall and Sand Ocean.
Getting an 'A' rank is much harder if not impossible with non-mech characters in each level, Cosmic Wall