The story of Pokemon Crystal Kaizo is identical to Pokemon Crystal, though with changes to the maps, movepools, and rosters to every trainer.

With the exception of a couple of rival fights, all major bosses have full teams of pokemon with improved movesets, all of which are shiny, and many of which use held items. As you progress, the gym trainers and gym leaders will have more wild cards that counter types that are super effective against their specialties, uses moves related to their specialty types, or pokemon that share similarities (such as cute pokemon, nocturnal pokemon, bipedal pokemon, dragon-like pokemon), or a combination of everything.

The Odd Egg will always reward you with a shiny pokemon. The Daycare Man, on the other hand, will only give out one of nine random pokemon, with two tyrogues with different dvs.

The Bug Catching Contest offers a much larger variety of Bug pokemon to catch.

Trade evolutions can occur through leveling up, or Politoed and Slowking can evolve from water stones. It’s also worth noting that eeveelutions get the first stab moves at level 20, and Espeon and Umbreon evolve through Sun Stone and Moon Stone (though their displays don’t show it, it works). Evolutions stones can also be purchased at the goldenrod city department store.

Map redesigns, including new dungeons and some perilous routes. Notable is the boulder in Mt. Mortar, where you can’t immediately use strength by conveniently talking to it, but must go through your party and manually select strength.

It becomes more difficult to level up around level 60, so there are lucky eggs and exp share available past the red gyarados. You can grind on wild lv 100 magikarps with increased exp gain near the last gym leader to grow levels in conjunction with the lucky egg.

When you reach the Elite Four and Champion, the game becomes extremely difficult. You’ll need to use all of your wits and a variety of types, lv 100s, held items, and regular items. Memorize berry locations and farm them as much as possible, as they will help you in battle, especially mysteryberries.

Following the Elite Four, you will face very powerful gym leaders, many of whom will use at least three specialty types, with a couple of exceptions involving wild cards that will prevent sweeps. There are four superbosses in the post game, two of which are in Viridian City, one at Mt. Silver, and one at the elite four on Mondays and Wednesdays. It would be prudent to plan ahead of time for these bosses.

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