I lost my post the first time I tried to answer that Alan mate (and there may be quite a few edits to this one) but would say that Contagion's the modern ZPS still and that kept me playing. The larger maps and improved MP handling through Steam have also been a great help along with the achievement goals actually being difficult for the level completions when playing solo at Hard difficulty. On Hard there is no L4D2-ing your way through Contagion in a mad speed rush, you are just signing your death warrant and that of your team when you hoard ammo and essential pickups and run off to be a lone wolf in co-op and fail to share resources around.
It also helps that for the original escape maps anyway the gate system had two endings so you could practice for either and even if you hit Youtube for a walkthrough the Z's are randomised enough to make every game different according to the randomised location of 90% of the pickups and ammo/tools etc. Maybe the game held more of my attention for lacking much hand-holding of any kind, you have to go into a deathmatch (Hunted) map solo and practice the weapon handling against the Z's and generally fire into the wall for the automatics, that way you don't struggle when playing Co-op and having to conserve ammo for the specific group rushes. [Easter Edit] and now I've finally added a working mic after over 280 hours it's like playing the game all over again for the first time as communication is a million times easier, so you can go on recces and cover each other against rushes with only the occasional superfast Z to surprise you on Normal difficulty.
However for all the love-to-hate jibes aimed at Activision with their COD DLC policy, when you pay for DLC it arrives on a schedule, when the DLC is free as it is for Contagion that's great but you wait and there is no cover when the devs have staffing changes, rights issues over assets or any other problem that causes long delays. The dev is also working on their next game which I will also look to support at launch like I did with this one if there's a good price so there will be as many maps coming from the Workshop community as the devs when averaging out how long the Contagion maps and the Flatline mode have taken to drop.
If it drops to £2.99 on Steam or less in Humble Bundle at Easter then I would say go for it but learn to aim and only play on Hard difficulty when used to the controls and then you will get the most out of it (despite dying a lot
). I'm only going to be back playing it properly after a reinstall but we can *try* to organise an Easter play if you know you're going to pick it up because when a team is really gelling together and playing like a unit and not getting themselves killed trying to be a hero with a melee weapon or wasting ammo like it's L4D then Contagion's still a great experience. I'm looking out for Flatline mode to have some more maps if they don't have to be as large as the most popular Escape type of map.
Keep checking the Steam Community thread as well because some Humble buyers dump their keys if they get duplicates or multiples.