>>33456637I would add some more points:
- important moves are learned on pointlessly high levels
- E4 is weaker and recycles some members
- some gen 2 mons not available in Johto
- introduction of baby Pokemon but only for some species, while you can still hatch fully developed Pokemon like Snorlax, Kangaskhan or Heracross from an egg
- some Pokemon species are limited to only one gender, there is no explanation how male-only Pokemon are supposed to breed in the wild
- Nidorina and Nidoqueen cannot breed
- introduction of "no Pokemon design left behind" philosophy, with many half-assed gen 1 rejects/shitmons making it to the dex
- introduction of evolution via trade when holding a specific item
- introduction of evolution via happiness, which cannot be reliably tracked without help of an NPC
