It's one of my favorite NES games too, I would probably like it even more than the original Pokemon Yellow once it's done being translated.
This is the only Pokémon port I actually liked and found time to invest due to how well made it is compared to the other ports I have come across by other Chinese companies. It does become something of a challenging grindfest when Pokémon get much higher in levels though. This is really noticeable when Pokémon start reaching around the mid 30's, the required amount of experience increases significantly to the point it would take a good amount of time just to get an extra level, and even higher level opponents feel like they aren't even giving enough experience. My level 37 Slowbro needs 10,935 EXP just to hit the next level. Compared to one of the real main Pokémon games, where any monster at that same level needs only 4,219 EXP (or more or less, depending on the monster's growth rate) for that next level, that's over twice
the needed amount for the next level. The experience growth is vastly different compared to the official games. You can imagine that raising mons in this port, will become even more of a project because of how much higher the requirements rise after each level. This is one of the gripes with this port that I have.
Finally managed to get a desired sixth Pokémon into my current party, but when one of them got a status condition, I decided to switch out with another, then I came across this bug, the levels displayed that would be showing a status, are messed up. This appears to happen when you have the player has a full party.
Also, came across another bunch of trainers that have Pokémon that make text garbles, both big and small when sent out, while I was out clearing trainers out in areas I haven't been to yet. It would appear these certain Pokémon are causing the garbles from what I can see, as shown with some screens here.
I came across this while battling a Rocket, and also thought this would be worth bringing to your attention in case of any possible relation. The move that was being used by the opponent that unveiled this oddity.
Also worthy of note : As I was traversing the Pokémon Tower, the last two top floors of it had different music not fitting to it.