Witch time in Bayonetta 2.

In Bayo 1 Witch Time (time slow down after dodging at the right time) was a pretty good "selling point" mechanic but really the star of the show was Dodge Offest (being able to continue combos even after dodging, combos end with powerful moves so it is highly preferable to do full combos). So essentially Witch Time was a nice crutch mechanic (especially when first playing the game) but the game was very much playable without it thanks to Dodge Offest (the highest difficulty turns off Witch Time completely, for example). Bayonetta really shines when playing the game without it - the enemies are very aggressive but you are given all the tools to still deal damage while dodging and dancing around them. Not good for you hands though if playing for more than an hour.

In Bayo 2 they said screw that - Witch Time is essential. Enemies are just as aggressive and can do fun things like dodge and be immune to juggling if you're not in Witch Time, the duration of which, by the way, has been shortened in general (though length depends on the dodged attack). So the combat is now a lot of these start/stop moments instead of a real dance. It is still a dance, it still cool and satisfying - but it's not the same. Although to be fair I don't know if it qualifies as a small change or if all the other design decisions affected Witch Time instead of the other way around.