Is this game for fishing enthusiasts? Eh, maybe for casual ones. It still has fishing tag, but same as Dave the Diver is not really a diving simulator, Dredge is mainly exploration game with fishing as central mechanic, but process of getting fish is done via minigames that have no connection to fishing. What you actually explore becomes evident mighty fast as world of Great Old Ones with all the things that come with it - lots of mysteries, creepy things, eldritch horrors and not really any way to fight that.
So - gameplay is all about sailing between islands and catching various sea critters all of which have eldritch mutations, there are several biomes with their respective species and several types of fishing areas like coastal, shallow, mangrove etc. all of which need equipment that would allow to get game there. Besides fishing, there are also traps to catch crabs and such and nets for passive gain, though some species could only be gained via trawling, so you’re sometimes forced to brave seas for a long time hoping to get lucky, since there si nothing you could do about it, but just go around and wait for net to “ding”. Ofc just collecting water dwellers is pretty boring, so there are quests to do and encyclopedia to fill, you’re gonna be asked to catch specific things, transport sometimes, find stuff. Besides living, there are also materials to dredge from waters, and those are used to modify your boat or to make consumables. There are also several abilities you could gain throughout the playthrough from simple turning on the ship light to eldritch speed or banishing magic. And as mentioned above - there isn’t much you could do when encountering enemies in Dredge, there aren't many of them and more properly they should be classified as environmental danger - tornado is pretty much same danger as giant angler fish that is disguised as fishing boat.
Plot is not that central and side quests are mostly rather simple, even if some are with eldritch flair. Ending becomes more apparent the further you go through storyline, what’s a bit more interesting are lore messages and nots on some of mutated fish, they sometimes give glimpses to broader universe of cosmic horrors. Just in case it’s not apparent yet - you begin as simple new fisherman in this region and start doing plain catching quests and paying off your loaned boat, since you apparently wrecked one you traveled on, but ofc things change rather soon.
Audio is okayish, though it’s kinda same for most of games to be honest, sound is almost always there to assist with ambience, only few outstanding titles have it either incorporated into gameplay or being just unusually good that it’s very noticeable. Dredge actually has some sounds being used as game mechanic that could alert you to some dangers before you see them, though osts are not much to write home about.
Graphics could be separated in two parts - stylised illustrations that look like painted pictures with mostly despair vibe to them and 3d world that is pretty simplistic looking in both design and details. It’d probably not get mixed with other games for the most part, but 3d does look rather generic.
