If you never played this game before, move along. Nostalgia is sadly the only reason I can possibly understand for all the positive reviews.
This game technically plays fine. You can farm and fight and do things without bugs or errors. But mechanically, Rune Factory 3 is an exercise in frustration. It's death by 1000 cuts. Nothing you can single handedly point to as 'yes, this is why I dislike this game' but rather dozens of small annoyances that begin to pick at you.
Let's just take it from the top, and I'll try to avoid making a novel out of this.
Before you even buy the game, you can pay 10 more dollars for the "deluxe" version. Deluxe usually means "everything all together" and I'll freely admit my failure in not paying super close attention. Deluxe in this instance means you can turn on swimsuits all year long. That's it. Don't bother under any circumstances. You wanna see swimsuits that bad? Summer exists. There's plenty of save files, make your secret lewd purpose save file 10 saves down the slot if you must.
Starting the game up, the annoyances begin immediately. You have ZERO options in the game for settings. You can swap a button toggle around, and you can turn off music. That's it. No sound sliders, no button configurations. This also means that the sound effects and voices are never able to shut up. And you're going to get extremely sick of some of the voices. I don't care how deep your nostalgia is, and I don't care if you're a super hyper fan of dubbing. You cannot tell me honestly that you enjoy hearing RAINNNNNNNNNNNBOW from the artist or DISGUSTING DISGUSTING DISGUSTING from the fat guy who talks in opposites.
Yes, there's people who talk in opposites. You can marry one.
You'll hear "good morning" from everyone and yourself. You'll hear your character say "poison" on EVERY SINGLE time he gets poisoned. You'll hear some extremely high pitched tings from healing spells because the sound engineer never existed. You'll hear the success and failure sounds from crafting exponentially more than what you want to. It will slowly drain your patience.
Moving items into your shipping bin is straight up a chore. You have to open up your toolbar, move to the item you want and throw them into the bin one item slot at a time. No just opening the thing and throwing it all in in seconds. Selling a decent load of stuff takes a minute or more easy. Each time. To make it even more time consuming, your cursor is always on the top slot of your backpack, so whenever you sort your backpack with the push of a button, you're likely always having the cursor on items you want to hold onto like food items for the day to eat and restore energy. Go past them, every single time, slowly slide thru the toolbar, grab a single slot of items, repeat. Unacceptable.
Crafting is a critical part of the game. You need to grind levels for medicine, cooking, making weapons, making accessories... and it's a mess in so many ways. The game HEAVILY leans into crafting to make money, since it also gives you experience to make better items down the line as well. Fancier meals. Higher tier tools and weapons. Outside of selling items "raw" to arbitrarily fill in the shipping list, you ALWAYS want to be manufacturing them. Why is that a problem? Because you can only do it one at a time. This is easily one of the most confusing design choices of the game. WHY?
Example: You can effortlessly get 100+ turnips in your field at the beginning of the game. Cooking them up is one of the very first recipes you can get at beginner level cooking. The game is aiming to you to make this your introduction to the cooking and farming systems. But you're also cooking the stupid things one at a time. 3 button presses, 3 seconds wasted. EACH. TIME.
Eventually you can level up your crops by sacrificing one of them to a scythe to get a seed level up. Sell that seed level up and the store now permanently sells that higher level seed. Get up to level 10 on turnips, and you'll have infinite money. Either keep a plot of land growing turnips all year long in the spring season dungeon, or just wait until the shop is randomly selling turnips themselves and buy all that you can to cook and turn around and double/triple your profits for as long as you can keep your patience doing this one at a time.
This isn't cheating because the game has a ton of ways to get infinite money. Be a drug lab and buy herbs for 30 gold a pop and turn em into increasingly more expensive medicines as your skill level goes up. Be a bakery and make a super ton of bread. All crafting skills are effortlessly easy to level up. Those two ideas alone already make up 50% of the crafting skills. Need to work on weapons or accessories? Make easy single ingredient items and upgrade them with scrap metal or enemy drops. The more you upgrade a single item, the more difficult it gets to upgrade it again. Those difficulties from leveling a level 5 sword to level 6 with garbage gets you more experience than actually attempting to mine "appropriate" difficulty level with 4-5 items requirements each.
Speaking of difficulty levels, you get recipes at random. You literally buy loot box style items that randomly give you a recipe anywhere in your skill level range. The first time I played the game, I got apple juice on day 5, which let me pick 5-8 apples a day, for free, and use them to regenerate my stamina 4 times a day. On my second run I didn't get that recipe until day 34. The random recipe unlocking is just yet another annoyance because you can only buy so many a day, and a lot of recipes are stupid. Every single fish in the game needs its own individual recipe to chop the thing up into sushi, for example. My apple juice example? There's also other juices like orange and fruit juice. These things add up to yet more frustration because you're wasting multiple days on these barely there changes you shouldn't realistically need a whole new knowledge set for.
Last one I'll actually go over is lumber. Lumber is baffling in this game. You need roughly 2000 pieces of lumber in total to buy all the house and barn upgrades. How do you get? You have to keep checking farming plots every day and clearing them of all grass and herbs and weeds and hoping that every so often you'll get branches for one lumber or stumps for 12 lumber to spawn in instead. You can't buy it. This adds yet another randomization to the mix, making progression luck based instead of skill.
I could go on and on with all these little annoyances. There's plenty more. Magic is barely there in the game. Requests will freeze up story progression and even doing festivals. Progression feels random and staggered. But you get the point by now. Don't bother with this.