Ok, definitely download the demo. This game rocks.
So it starts out that your dad takes off to be an adventurer, leaving you apparently all alone in this shop. A fairy/loan shark comes by and wants the money they put up for the place...which you dont have. Instead of just kicking you out, you decide to run the shop to earn the money to pay them back. At first they don't tell you how much you owe total...but its really not important. There is a weekly payment due so your job is to earn at least that much before the end of the day on the due date.
Each day is split into 4 time blocks (omg TIME CUBE), and you choose what you want to do in each block. Leaving the shop takes 1 block, but there are places you can visit once out that dont take any time. Going into the dungeon takes 2 blocks so if you want to go you have to decide early in the day since you need enough time to get back home.
So the buying and selling of items is pretty standard stuff. You put items out in the shop, and people come in to buy them. Every item has a base price. You generally want to boost that up a little to make some profit, but too high and the customer might decide to not buy. There is some haggle room where they might not take your first offer and you can lower it and get them to bite. Same thing happens when an adventurer comes in to sell you something, only you want to lowball them.
Then you get customers coming in that ask for certain items, like a hat. These don't have to be on display, they just come in and ask for them. It sucks though when you don't have any of the type of item they are looking for so its probably a good idea to keep a couple of everything in your inventory.
Getting items to sell is the fun part. You can go to the merchants guild and pick some up, but you pay the base price so profits are slim. What you really want to do is hook up with an adventurer and go into the dungeon! I would say go in there as soon as the game lets you because its really the hook. Its like a roguelike with random generation, traps, enemies, and various floors to explore and clear. Unlike most roguelikes its entirely realtime and smooth moving. You run around and hit a button to swing your sword. Killing enemies drops all these gem looking things which are apparently XP. Sometimes you'll trigger a trap, which you can move to avoid. You want to explore and kill a bunch so enemies can drop loot or chests will give you loot. Every 5 levels or so you get a door to the surface so you can take all your stuff and sell it in the shop. If your adventurer "dies", then you can only take one item out to sell. So be careful! I died my first time in the dungeon and didnt have much to show for it and it wasted almost an entire day. By the end of the demo I was living in a cardboard box.
The obvious nice thing about selling dungeon loot is whatever you sell it for is pure profit. Well...not exactly true. You can buy healing items and the like to help your adventurer to survive but still, lots of money to be had.
So yeah, play this demo. Its great. The selling portion isn't as hectic as those time management games like Diner Dash, even though the game overall has some time management in it. The dungeon gameplay could be a standalone game all by itself and it would be fun. But the fact that they are in one game where you find these items and sell the loot...its just fun as all hell. Looking forward to buying this.
EDIT
Oh yeah, the custom.exe file in the games folder is so you can change settings and controls. Might be worth doing. This game works great with a gamepad (I used my 360 controller), as the mouse has no use.