Alright remasters of the GC era RE games
2002 RE1 REmake is THE monumental video game remake that started the entire boom, and is still the gold-standard blueprint for how to remake an older game to many of us older gamers. It was designed by the original creators, for the veteran fans of the original trilogy, and kept the original play-style, story and vibe of RE1... yet changed and expanded EVERYTHING in order to surprise and challenge even the most experienced players. It's NOT a "replacement" for the 1996 RE1, but rather a brilliant, next-gen "NG++" for the classic game.
The RE0 on the other hand has always been bit of a black sheep of the series. Originally an N64 exclusive, soon moved to NGC instead, Zero was an all around more experimental title that didn't fare too well. You play as two characters simultanously, and need to switch between them all the time, all while the iconic Item Crates seen in all other RE games are now gone and replaced with an option to drop items anywhere. While this sounds swell on the paper, the experience is rather tedious, made worse by the very forgettable world design.
Story-wise, RE0 also brings a lot of nonsense sludge into the lore of the series, practically exaggerating things into anime-level silliness and undermining the simple yet effective backstory of RE1 itself. Which is why I often recommend people to skip Zero and Code Veronica.
What comes to these HD remasters... they're serviceable, but not flawless.
REmake 1 HD came out in 2015, and was made without access to the OG assets, nor were there any sort of AI upscalers available yet, meaning the old 480p backgrounds and FMVs were merely "Photoshop upscaled" to look more "HD". This means that some scenes are very smudgy and low-res anyways, with the by default pretty high-def 3D models sticking out like a sore thumb. The devs tried to compensate by adding a very strong color-filter + film grain effect on top, but this ends up making the game even more monotone and grainy.
Not only that, but many gameplay elements were changed, often for the worse. The introduction of this new difficulty mode, Very Easy ("Walking") means that many newcomers believe the original "Easy" ("Hiking") to be the "Normal" difficulty.
Not only that, but the new "modern" control scheme, which is essentially the directional 2D control scheme found in games like SH4 and DMC, is now the default, and completely breaks the game. You can fortunately still switch to classic tank controls (3D control style), but few newbies probably will even humor the thought of doing so, meaning they'll have to make do with the more janky and ugly movement style.
RE0 HD fares a bit better, with the BGs and FMVs actually being properly re-rendered at UHD quality this time around. There are some questionable visual changes to some characters, and all the silly, casual additions already found in the REmake HD, but it's still a passable way of experiencing Zero ... IF you must play this last classic-style RE game.