Single player is actually really fucking good, at least on par with if not better then any of the serious sam games. Map design is good at least so far, first two missions are kind of linear but then the third mission is actually a real maze-like doom map with gotta go find keycard sections and shitloads of hidden secrets. I played through the first two missions then did them again to 100% them and then did mission 3 100% and it's taken me 6 hours so far. Gameplay is great. Worries about being forced to do melee kills animations to get health and ammo are completely unfounded, the melee kills give you jack shit and you have to not get hit in the first place and hunt around for ammo packs as you fight.
Multiplayer is more or less what we saw in the beta, it's not gonna hold up to quake 3 as an esport. Snapmap is more of a mario maker co-op style ordeal limited to 4 players, which will be really fun but it's not going to allow us to rebuild cpma unless you only want to play 2v2. Really hoping they bring out proper mod support for the multiplayer because otherwise it'll severely squander the success of the single player section.
Also the music was done by the Killer Instinct guy. So good.