Complex sentence: Much of the gameplay in "Ar tonelico II" is very similar to that of the first game, but overall the game has undergone huge changes in battle system, graphics and most importantly, Cosmospheres are now very closely linked to the plot advancement.
Split into simpler sentences: Much of the gameplay in "Ar tonelico II" is very similar to that of the first game. Overall the game has undergone huge changes in battle system, graphics and most importantly, Cosmospheres are now very closely linked to the plot advancement.