Okay, here's what the top screen looks like when you're messing around with Ability Link. You use L or R to cycle through the three Spirits currently in your party and see their stats.
On the bottom screen, you have a kind of roadmap of abilities that you can purchase using Link Points. Every Spirit has a different map, with different abilities - usually ones that correspond to its own abilities. (For example the fire-breathing seahorse-thing has a lot of fire-related abilities and powerups on its map.)
From the roadmap you can buy abilities using Link Points. You start at the keyhole and move around buying abilities as you go. The abilities in bubbles are ones you can "reach" at the moment on the map; the ones encased in ice are "frozen" and you can't buy them until you've bought one of the abilities adjacent to them. In the picture below I've got my cursor over a command, Soul Release. The bubble above is an HP UP, and to the right is an Attack Haste.
If you have enough Link Points you can buy the abilities for the amount of points shown on their bubble. Here you can see me buying the Attack Haste; my Link Points (shown in the top right) go down from 176 to 126.
Sometimes the map is blocked by gates that only open when you satisfy certain in-game criteria. This gate won't open unless the Spirit I'm using is at least level 30:
This one won't open until I've performed link attacks with this Spirit at least three more times:
Some Spirits also have gates that you need to pay a certain amount of a certain item to open up.
I'll get some shots of the breeding screens/menus next time I have enough materials to breed a new Spirit
What are your final impressions on the game?
Edit: also anything intresting in the character histories?
I really enjoyed playing it, but I'll write up proper impressions later. I haven't seen anything interesting in the character bios yet, they're all pretty basic :/