[Perma-unlock Round Ears]

My  understanding is that it is impossible to get Round Ears in Sandbox mode.  How about perma-unlocking  them (at least in Sandbox) once the  player has acquired them through story mode?  Sort of a lasting achievement for beating story mode.

[Green Star Sparkles with Glitter Sound?]

That  explains it!

[Green Star Sparkles with Glitter Sound?]

I  keep hearing this "glitter" or "magic sound"  in my game and then I just saw a bunch of green start sparkles around  one  of my nichelings.   Am I imagining things?

[Simulation Mode]

I  would love this! Sort of like wolfling runs in in the old Creatures  2.

[Toxic Colors are Heritable]

Instead of having toxic body colors  be random,  have them  be heritable, like  regular fur colors.    Programming-wise,  perhaps have toxic colors correspond to regular fur colors (beige=yellow,  chestnut=red,  moss brown=green,  etc.), so that  there's just a toggle as to whether  it  is the bright toxic color or the regular color.    This system would also let you could get intermediate colors, like toxic orange.   White and black could serve as modifiers  making pastel  or darker (but still  bright) colors.

It just doesn't make any sense that my toxic tribe is totally psychedelic (unless  they've been  grooming  each other and are hallucinating).