Around 6 months ago I repaired the Gameboy seen in the photo and videos and recently I've been playing Pokémon again after all these years. I'm wondering if it's normal for Pokémon or some older games to have what appears to be a greenish pixel takeover in certain parts of the game? 

I had to solder a new battery a few days ago to get the save files up and running however I'm worried that either the game cartridge or the Gameboy is somewhat damaged or on its way out? 

I had never done any proper testing when originally fixing the Gameboy itself (playing a game for awhile to see how it is). Both the internals of the cartridge and the Gameboy are clean and don't look corroded as I did thoroughly clean and refresh areas that needed new solder and a good clean. 

I'm worried it might be the Gameboy itself but I'm still rather inexperienced with repairs and I'm rusty around og Pokémon games so it may have been the norm back then for the game to look a little trippy/glitchy in certain places but hopefully it's just that. Eventuallymi want to get a Gameboy with the light up screens you can build yourself however I'm old fashioned and somehow have the kid that plays it how I played it oldschool like many others.

Sorry for the lighting and camera angles it's quite hard to get gameplay without the focus and lighting to go against me lol.

It won't let me attach a video so I've attached photos. The waves on the ocean kind of bleed out a little with the animation which looks a little extreme and when playing at times there can be a faded green to pixels/ Pokémon and also on the sides of the screen around general game areas.

Any tips or advice is appreciated. 

(Pokémon Silver) Do I have an issue with either my Gameboy screen or Pokémon game cartridge?