Autobattlers are always really fun to play! I wish there was a way to release parents back into the wild or breed child turtles together. If you ever make endless mode, you should definitely consider randomizing parts of Vedals together for more combinations. I think also explaining what the benefits for choosing which turtle will be on top or bottom when mating them might help too. Beyond that, it's a really fun game!

This is really well made.

I did manage to crash it by left/right clicking on the “You win 1/6” screen though, here are the logs:

Unhandled Exception - uncaught exception: { message : "unable to mod with zero", longMessage : "unable to mod with zero", stacktrace : [ "function yyError("unable to mod with zero")
","function yyfmod(0, 0)
","function gml_Object_oPlayerTurtle_Mouse_5([instance], [instance])
","function(1541, 0, [instance], [instance])
","function(1541, 0, [instance], [instance])
","function _su2()
","function _pw3()
","function _Wv3()
","function _pv3(404996.1)
" ], script : "", line : -1 } in file https://html-classic.itch.zone/html/12379732/html5game/Neuro-Sama%20Tutel%20Rancher.js?cachebust=891464743 at line 1099 Neuro-Sama Tutel Rancher.js:1097:224
###game_end###-1 Neuro-Sama Tutel Rancher.js:1097:224
Uncaught 
Object { gmlmessage: "unable to mod with zero", gmllongMessage: "unable to mod with zero", gmlstacktrace: (9) […], gmlscript: "", gmlline: -1, __yyIsGMLObject: true }
​
__yyIsGMLObject: true
​
gmlline: -1
​
gmllongMessage: "unable to mod with zero"
​
gmlmessage: "unable to mod with zero"
​
gmlscript: ""
​
gmlstacktrace: Array(9) [ 'function yyError("unable to mod with zero")\n', "function yyfmod(0, 0)\n", "function gml_Object_oPlayerTurtle_Mouse_5([instance], [instance])\n", … ]
​
<prototype>: Object { toString: toString()
, … }
Neuro-Sama Tutel Rancher.js:1099:159

This is awesome!
Vedlian and Vedolf are my favourite couple so far.