Played throughout pre-hardmode. Here is a couple of things I can say about the mod:
BUG: The new enemies in the Dungeon don't know how to open doors (at least that slower skeleton can't), which is odd considering there are doors there and vanilla enemies can, this should be fixed.
The armor sets so far are interesting. Not a big fan of the petal set though, the passive is good but I have a feeling it's just worse than the Jungle set which is much easier to acquire. I'm not calling for broken stuff, especially at Jungle tier level, but it felt silly farming those petal enemies for about an hour when I could have just made a better Jungle set much earlier.
The UFO thing you can make with the Strange Alien drop is incredibly powerful. A spell that lets you target whenever and also lights up? It's just a better Crimson Rod. I love it but I wouldn't call it balanced. The Blood Boiler at the end is an upgrade to the Rod too but that requires 4 staves and is really hard to acquire, not to mention it's mana hungry, so I'm ok with that. The Jungle one is also great and might be my favorite weapon so far. Not a fan of the corrupted counterpart to the Boiler though, felt too situational for those stars to be good.
I like most of the NPC enemies (and villagers too) but the two bosses are kinda mediocre. OK fights but they really don't stand out, especially now on Expert. The snow spider never spawned so I dunno about that.
So far, mod is pretty good.
I may talk about Hardmode later but I'm trying a run as a mage using purely Thorium spells and killing the WoF is being near impossible.