PASTEBINNED FOR YOUR CONVENIENCE

Characters can be earned through regular play. They have been so since March 2015.
This'll be wordy, so here's a TL;DR:
Game is essentially reskinned Gundam VS; slightly dumbed down mechanics-wise to introduce it to the western-audience.
DX11 Graphics Cards ONLY
This game is not pay2win. There's no way to pay for direct advantages over other players.
Character purchases come lightning fast due to all the rewards you get to leveling. If you play a variety of characters, you'll easily have more than enough currency that you'd ever need. You also get a week or two's worth of full roster access to start with.
Controller highly reccomended, but not essential.
Skill Cubes are basically placebos unless you minmax and dedicate entire loadouts to a single stat. Where they then become minor improvements (like 20% more damage for ranged attacks). Not at all a game-changer (no "they only won cuz they had better gear" stuff), but enough for EXPERIENCED players to notice slight differences.
Skill emphasis on player positioning/spacing/movement and timings/prediction, rather than flashy button inputs/raw aim. Very easy to pick up, but with a huge skill gap between "good" players and "bad" players.
Little to no grind.
Game has that... "polished feel" to it despite any bugs. It doesn't feel cheap like your average F2P game.

About 2vs2 Games
Rise of Incarnates is Bamco's first "real" attempt at introducing the long-running "2vs2" genre (commonly assocaited with the even-longer-running "GUNDAM" franchise) to a western audience.
To those unfamiliar with the genre, VS games are 3-dimensional brawlers where two teams of two go head-to-head in an attempt to deplete the other team's "life gauge" through killing their opponents. Killing your opponent means they have to take a portion of the life gauge so they can respawn.

If you're unfamilliar with the 2vs2 genre, there are a few games you can draw some parallels from:
Dragonball Z: Budokai Tenkachi
Gotcha Force
Virtural-ON
Don't go into a 2vs2 game thinking it's a solely a "punch-up", however. Ranged combat is important, if not the primary aspect of many a character's toolkit.

A key aspect of 2vs2 games is the "life gauge" system. Different characters require different amounts of the life gauge to respawn. With the more "powerful" characters having the drawback of taking significantly more life-gauge to respawn.
Rise of Incarnates' take on this is the "stock" system. Each team has a stock bar consisting of six units. Characters range in respawn requirements from one to three units. So while a team of three-stock characters has more "oomph" in all departments, they only have to die twice between the two of them before they lose.
Lower-stock characters, while generally "weaker", have more composite health spread across multiple lives (i.e, a character with a one-stock value and 250 health has a total of 750 health across three lives, as opposed to a three-stock value character with 600 health).


About Rise of Incarnates
Now to talk about this game specifically?
This game shows promise.
While slightly "dumbed-down" in comparison to the latest Gundam VS title. It's still quite fun to play. It's also the only game of it's kind available on the PC market currently, so there's that.
"Purists" may not appreciate the game though for the absence of a few features (that I myself am not greatly familiar with as I've only emulated a few of the PSP titles), and that's understandable.

Players have a wide variety of tools at their disposal to deal with enemies:
A ranged attack
A melee attack that can be influenced by the player's directional-input
Two special attacks which can be activated by holding down a another button and pressing either the ranged or melee attack buttons respectively
A "special" move which varies in function between characters. For some it's powerful attacks, for others it's mode-switches, for others it's temporary transformations
A "tag" attack which requires initiation by your teammate
The properties, aspects and intended use of these moves vary between characters. Enough so that most people will find a style they like.

Characters
For the first day after a new player logs in, they are given full access to the game's entire roster for 24-48 hours(?). This can be extended to a 14-day period by completing additional tasks relating to advanced techniques such as evading enemies attacks using your own, or attacking enemies during vulnerable moments (confirmed).
After their free-period is up. Players can pick one character to unlock permanently for free. And there are always two characters on free-rotation weekly, so a player will always have at least one additional character to play as.
Players can unlock characters wtih LP AND IP. With LP purchases, the price for each character steadily increases the more you buy. Starting at 200k, then 300k, then 500k and so on.
After you log in on 20 days (doesn't have to be consecutive, I think) for the first time, you can buy a character for 99 IP which is like less than a dollar.

Skill Cubes
A unique feature to Rise of Incarnates is the "Skill Cube" system. Players have a single grid (although you can buy more grids so that you can quickly swap between presets) that they can freely insert and remove skill cubes from which improve various aspects about the character, ranging from lock-on distance, to damage, to mobility aspects. Skill cubes have a limited number of uses (fights you take them into) before you need to recharge them by fusing other cubes into them, which transfers the uses-remaining of the fused cubes into the depleted cube. You can also enhance cubes - increasing their effects and number of uses-before-depletion - by fusing other cubes into them.
These fusions take real time. Low-level fusions take only a few minutes to perform, but this time rises expoentially. The time caps at roughly 3 hours per fusion at the highest levels.
You start out with two "queues" in which you can enhance, combine and recharge your skill cubes. This means for completely free players, you can up to two things going on at once. This can be increased to five queues through using the paid currency: "IP". You can also use IP to instantly complete these fusions.
Additionally, there's a neat little feature where completing an online match - win or lose - will reduce the crafting time of all your active queues by an extra 15 minutes. This makes it so that the timewalls pass by faster for active players.

The skill grid starts out as 2x2 in size. But expands bit by bit as the player levels up, eventually resulting in a 3x4+1 sized grid. Players CANNOT buy additional squares on the grid through any means; they can only buy XP boosters to accelerate the leveling process, which means jack-all if they can't win to take advantage of it fully.
The stronger a Cube's effect, the more space it takes up on the grid.
Players earn skill cubes after every fight. One for a loss, two for a win. You can purchase skill cubes you've already found once from the marketplace at their base level. However, this only applies to basic cubes. Rare cubes such as character-specific ones are at the mercy of the drop system.

Cubes overall are cool addition that helps to add a metophorical "carrot" for players. Although while the numbers are not even noticable until stacked heavily, they do provide an advantage in a multiplicative sense, which amplifies the potency of the already-existant advantage that skilled players have over not-so-skilled players. Cubes don't mean jack if you're a baddie.

Multiplayer
Multiplayer consists of:
Custom game lobbies.
Player VS Bot (can be tackled solo or with a steam friend).
Ranked matchmaking.