For many current and former players, these two games represent the pinnacle of the video game series. While these games advance into a new region, they maintain the feel of the original games, especially with the artistic style of the 100 Metal-era Pokémon, the ability to go to Kanto after beating Johto, and the ability to trade Pokémon to and from R/B/Y and G/S/C.
However, they also introduced new ideas and precedents for later games. The day/night cycle was profusely praised, because players liked the added strategy of catching different Pokémon at different times of the day. Its removal in the third generation was met with much criticism, but it has been restored for the fourth generation. The inclusion of the “radio” for listening to different music while not in a cave was also missed in the next generation. Additionally, the concepts of item holding, breeding, an internal clock, special “shiny” Pokémon (though without the inheritance of the trait through breeding), an EXP bar that shows how much EXP a Pokémon has to obtain before leveling up, Pokémon genders (male and female) and others have carried over to later games.
However, the battery used to power the clock is not rechargeable, and so the battery will inevitably fail and the save file will either be deleted or corrupted. This was first noted in emulation of the game. Now, many players have already reported the battery failing. It can be replaced with a standard CR2025 watch battery, although this requires opening the cartridge, removing the old battery, and soldering the new battery to the battery tabs.