On my second playthrough now. Chapter 10. Going for all the Achievements (except finishing on Hardcore and that other mental setting). Got 82% of them so far.
It's great you can take your built up character through to the next playthroughs with all their weapons etc. Makes it easier upgrading them, but then pushes you that bit more to complete it at least 3 times, as that's what it may take to get enough deaths or stomps for the full Achievement list.
Things I need now are firing a necromorph 17m and pinning him to a wall, having 4 upgraded weapons at the same time (this one could take a while - I currently have fully upgraded Stasis, Rig and Line Gun. Need another 3 weapons fully noded out!), Finishing on zealot and hardcore difficulty settings, Decompress 20 Necromorphs without getting sucked out yourself, Kill 30 Necromorphs with Kinesis objects and Kill 30 Crawlers without detonating them.