what makes it different than the other kiseki games?
Everything. The story and characters are the bad part of this game. This is an action RPG where you control a single character. The other games in the Kiseki series are modern RPGs that use a system they call "action turn" which is a lot like the battle system from Final Fantasy 10 and you control a party of characters generally.
Around halfway through the game, you always (for the most part) have access to four movement abilities that are a lot of fun to use. Some of them double as attacks.
Around halfway through the game, you have access to three (of the four) special sword attacks, the last one you get towards the very end. They're simple and fun to execute and can be used in various combat situations to your benefit.
You can use physical (sword) attacks and magic attacks, in any combination you wish. It's setup so that you don't have to look at menus too often.
There's a combo system that gives a bonus for stringing together lots of hits while avoiding attacks, which I like a lot.
There are 10+ boss encounters in the game. Each has its own attack pattern, and each one has a minimum of two fight stages. They are similar to the Ys Seven boss fights.
Each level has 3 large crystals and one chest that the game challenges you to find. This encourages you to explore levels. If you find some of them, the game will keep track of which of these you've found.
There's good level exploration music for most levels. There are 60 levels in the game and 15 different pieces of music for exploring them, which puts it similar to a Mario game in terms of quantity. The music is provided by none other than the excellent JDK Band, which is the name of Falcom's internal sound team.
This link will take you to the soundtrack.
There's adjustable difficulty so you can customize your game. "Normal" is the difficulty to choose for average players, and it will provide some challenge (I played on normal). "Hard" is quite difficult, and "Infinity" is really hard. "Easy" is too easy and shouldn't be picked unless you're a terrible action game player. You can change the difficulty at any time.
There is a system where you have to replay levels multiple times after the season has changed (up to four time). Indeed, the levels don't change at all when this happens. It sounds like a really bad thing but it's not. You'll find that, for example, because it is summer, vines have grown and blocked a path that was usable before, so you need to take a different path through the level that shows of a different part of it. The scenery is different because trees look how they should in the various seasons, lakes freeze in winter, oases form in deserts in the spring, etc...