Lets start with the positives. The overall idea and theme are pretty great, the map is clearly a parody of Fire red/Leaf green but different and more crisp and enjoyable to look at, and the designs for the "Oppaimon" are fairly good, the other female characters also look pretty decent.
Now for the negatives. This game has some serious base issues, not just with it being lagging or not being able to catch "Oppaimon" at all, like most of these comments suggest. The issue is with the map, and UI itself, as there seems to be no apparent grid like movement, which makes interacting with anything an annoyance, especially since all NPCs are not solid so you can walk through them and miss the area in which dialogue can be found. The screen tearing is also awful.
A word to the devs, from another programmer, I would seriously recommend ditching whatever platform you're using to make this game, switch to something more basic, even use RPGmaker if need be, use pokemon essentials and just switch the art, story and maps a bit. This won't actually change what your game looks like, but will also this make the game easier to update, program and manage, and more importantly also will feel much much more enjoyable to play then whatever the fuck this is. Switching would also fix alot of the lag and catch rate issues, just a tip
I want this game to thrive, but currently adding more content is the least of your worries