NOTE: I love this game franchise with my whole heart and I'm really happy that it finally comes to PC and the campaign is great as always.
However, multiplayer-wise I cannot recommend this game to anyone who's not familiar with the series and it's not solely because of bugs and I'll go over why.

The thing about the multiplayer is that many of the game modes and most of the DLC maps were never played as often because it wasn't really a good feeling to them or they were literally garbage, while here on PC they get favored by the matchmaking making me and A LOT of players frustrated.

Firefight Matchmaking is just horrible at the moment, I've played over 30 games of firefight and have not gotten to play a SINGLE CLASSIC FIREFIGHT, instead I just get to play ♥♥♥♥ like Fistfight, Fiesta Firefight, Grenade Firefight.

Multiplayer Matchmaking is OVERLY favoring the most hated DLC maps all the time, especially the map "Penance".
When searching for 4v4 Slayer only, you'll almost everytime get Team DMRs.. which isn't bad but boring since the DMR makes picking up weapons on the map "unnecessary" in lack of better words since the DMR is already EXTREMELY powerful, rendering almost every weapon useless except Rockets and Snipers.

Spawn points are definitely buggy at the moment, I have NO memories of spawning in front of enemies as often as I have done here on PC. It doesn't happen every game though but sometimes when people run around the map like maniacs the spawn points it tends to get wonky sometimes, this was true on Xbox 360 aswell, the difference with the PC release is that it doesn't stop being slightly wonky after it started and it actually get worse instead as the game progresses.

I somewhat expected aim assist on controllers to be broken in the beginning, but IT EVEN TRACKS THROUGH WALLS LIKE WHAT THE D*CK and locks way too hard onto enemies, tried it myself out and it's too much, please fix.

The armor customization unlock system is actually d*cking retarded and makes no sense.
Instead of credits and freedom of choosing what customization we unlock first, we are now FORCED into the "Battle Pass" system commonly found in Battle Royales but worse.
For every level you gain ONE "season token" to unlock armor, now you might ask yourself "hey, that doesn't sound so bad?" the thing is, you're forced to buy the item you unlocked instead, which just adds tedious extra time to use the token to unlock the item instead of just giving you the armor item instantly.

The leveling system is bad aswell, it's hardcapped at 8000 EXP for your game performance every match and it's a childs play to get to that cap, get one multi kill and a revenge kill and you're pretty much good to go.
This feels bad, really bad... especially when you get 20 kills and 1 death but you get the same amount of EXP as the dude with 7 kills and 10 deaths.
Like I said earlier, it just feels bad and it's slow as hell, but I can live with it.

But out of these things I've talked about there is only two of the things that really infuriates me.
* Aim Assist for Controllers needs to be adjusted.
* The DLC maps gaining some sort of priority over the old classic maps. My personal ideal solution for this would be an option to choose to filter out all DLC maps or 2-3 maps of your choice that you really don't want to play. I don't care if the matchmaking times becomes longer. I just don't want to play d*cking Penance 24/7.

With all these things said, I will continue playing the game since it's still a great game.
I can't actually say I'd recommend Halo Reach for PC to anyone who hasn't but wants to experience the nostalgic multiplayer everybody is talking about.
I can still recommend the campaign though, since it's fun and great gameplay.