Rune Factory puts a new fighting element that betters the game overall.
Near where you live there are many caves filled with many monsters, after you do the base requirements you get a pass to go to the cave where the monsters kill you in about 4 hits. But train and you can kill them in one hit!
Of course killing monsters isnt the only thing you will want to do, crops help you refill you're RP points which are lost as you do Physical Activities and use magic.
There are times when you just go through caves and battling there biggest monsters over and over, slowly getting stronger and maybe recruiting some helping monsters, and monsters for other purposes. Though slowly by merely talking to people they'll like you and girls will love you. You'll want to harvest lumber and expand your house, by doing this you can do much more things such as forge etc.
With heaps of food you can cook, accessories to make, weapons and tools to forge and medicines to make, you'll probably find you'll have spent a lot of good mostly fun, time trying to finish the game 100%