While I understand players want some new content (we all do, really), if you really think Achievement system took "nearly no time no time to produce", I'm pretty sure you're dead wrong. I think there's quite a bit of coding, quite a bit a creative tweak, rare boss system, and some extensive testing to be made both by the dev and the community. The threshold for the time trial, for instance, might sounds trivial but that only takes time to test and to set up.