I have probably mentioned this before, but both my brother and I are big fans of Capcom's Megaman series, and that includes the Battle Network and Starforce sub-series. As such, we have been playing Megaman Starforce 2 quite a bit over the last days, and I have really been enjoying it so far. I already have quite a bit to say about the game, however, since Battle Cards are so important to the game, they will be the first aspect of Megaman Starforce 2 I will discuss.
I really think that the Battle Card system of the Megaman Starforce games is a significant improvement over its predecessor, the Battle Chip system from the Megaman Battle Network games, mostly because it abandons the alphabetical code system. In the original Battle Chip system, every individual Battle Chip has a letter code in addition to the chip type, so you could have things like an "Cannon B" chip that is similar to, but slightly different from a "Cannon C" chip. All "Cannon" chips are used in the same way and have the same strength, but chips with different codes can be combined with different other chips. Because of that system, you can use a "Cannon B" chip the same turn as a "Protoman" chip (Protoman is always B), or you can use a "Cannon B" and a "Cannon C" at the same time, but you can't use a "Cannon C" chip and a "Protoman" chip at the same time. This means that there is an incredibly strong incentive to build Chip Folders using as few codes as possible, in order to maximize the number of Battle Chips you can use in one turn. This incentive is so strong that it practically overrides any other consideration, and often makes Folder creation an overly complicated endeavor. Also, because chips of particular codes may be more rare than others, it occasionally made gathering a good set of Battle Chips a lengthy process. This system worked well enough in the early Battle Network games, when building the Chip Folder was the player's only concern, but what advantages it had began to break down in later Battle Network games.
The big problem for the Battle Chip system came with the introduction of Style forms, Double Soul forms, and other such systems in later Battle Network games, as well as with the continued improvements to the Battle Chip list that came with each game. More and more, considerations like needing a large number of powerful Fire Chips to fuel the abilities of the FireSoul form or needing to include a mix of good Normal Chips and Electric Chips for ElecCross form began to create an incentive that contradicted the code-based incentive. More importantly, the code system made it difficult or impossible to freely use multiple forms with a single Folder. As a whole, the entire system ultimately promoted a limited set of "good" Folders based entirely on what was pre-determined by the game designers, rather than what the player desired.
Megaman Starforce 1 changed all of that when it completely abandoned the idea of letter codes and replaced it with the column rule. Now, in the Starforce series, Battle Cards are laid out as a grid of three columns of two cards rather than merely a list of available options, and cards that have been randomly assigned to be in the same column can be used together in the exact same manner as cards of the same code could be used together in the old system. As such, the player no longer has the option of gaining an advantage through careful Folder construction, which actually means the player is free to chose whether to use a Battle Card or not on the Card's merits alone. Unusual Card combinations are possible in a way they never were before, and Cards no longer have artificial synergy just because they share a letter code. What is more, these restrictions are eased while still preserving the original reason the code system was introduced: adding some strategic complexity by preventing the player from being able to use every card given to him in battle at once. In fact, it pulls it off more successfully because there is no way to work around that restriction in the Starforce system. It also preserves the "wild card" value of the old asterisk-code with the "White Card" designation. A lot of negative side-effects of the system were removed and almost all of the advantages were preserved.
One new feature of the Battle Card system that I find to be particularly good is the change made to the "favorite chip/card" system. Previously, the Favorite Chip was a Battle Chip that was guaranteed to be available at the start of battle, and it was often restricted by a numerical "memory" value that made it hard to make proper use of. In the Starforce games, this is replaced by the Favorite Card system in which you choose a set of four or six cards that become "White Cards", letting them be used more freely, with no over-complicated memory restriction. This change simply lets you use cards you like more easily, and it is a lot easier to manage than the old system, so I prefer it.
There is a lot more I can write about, such as the new Star Card system, but that will have to wait for another day.