The game has some good ideas, and adding RPG elements to a Titan Souls formula gave the world more depth, but there are far fewer bosses and the lack of precision seriously hurts the game. Way too often attacks won't hit or you'll fly in the complete opposite direction you meant to go, the grapple attack will hit the floor at your feet for some crazy reason, or you'll just stand there and do nothing. This is true for the bosses as well as pretty much every boss has at least one attack that does no damage and never hits for some weird reason.
It's just a terrific 2D, old school shooter. That's really all you need to know. Nevermind the Contra references. It's just plain good. I did find one level a little too long and repetitive, but that's not enough to detract from how great this game is. There's also a bunch of bonus characters to unlock and an easy mode for those of us with older fingers which is very welcome for those of us who grew up with the original Contra. EDIT: NEW MODES AND FREE CONTENT! The game has since received an update that has added a bunch of new modes and an editor feature that allows you to completely customize your run, and it has ironed out all of the few flaws the game had. And the game will be getting a free expansion soon. The value just keeps going up.
I don't want to be too harsh because the game is genuinely impressive and I thank the devs for their hard work making this possible, but right now I'd describe the game as unplayable. Incredibly buggy, crashes constantly once you leave the train, terrible performance, and I have to restart my computer after quitting the game because my system becomes unresponsive. It's not just hard on your hardware, it's hard on Windows, too. I do want to see more of the game, but I'm gonna step back from this one for a few months because right now it's unplayable.
I love Suikoden, and this game is very much a love letter to the franchise, but it feels like a game made by a bunch of amateurs rather than a highly experienced RPG veteran which is not the case given the game was directed by the series creator whom sadly passed away shortly before the game's release. Also, as noted by others, there are numerous examples throughout the game where the original script is completely changed to force a political statement which is completely contradictory to the original script. One example sees the characters comment on defeating a tough enemy, first victoriously exclaiming glee before remarking on the origin of the creature. In the original Japanese, it's just the characters wondering where the thing came from, but in the English script, someone calls the creature a "him" for some reason to which another character makes an out of the blue comment on gender profiling. It's an example of hijacking art to express a message that was never intended. If you're against the idea of changing art, then this game will infuriate you; however, if your only interest is a JRPG, specifically a new semi-entry into the Suikoden franchise, then you might find the game more palatable at a much lower price point. On gameplay alone, it's really not worth the full price.
I don't get why people are saying this game is so good. The controls aren't precise enough for the amount of precision the game demands, there is a distinct element of randomness to many of the fights, bosses can hit-and kill you-AFTER they've been defeated, and the hit zones on many things are wonky due to the way the animations work. The old school cartoony soundtrack and sound effects are MURDER on your ears. If you think modern cartoons sound terrible, wait til you hear old school cartoon sound effects. The best way to think of this game is like the Dark Souls 2 of the Souls franchise: it's good, but there are definite issues. The only thing the game really has going for it is the charming art style, but it gets old fast. If you think the idea the refighting bosses over and over again in Souls sounds horrible, stay AWAY from Cuphead. At least in Souls refighting bosses can be fun. Here you can get hit by a missile obscured by foreground art which is just infuriating and cheap.
The game is a turn-based RPG with an interesting premise: all battles take place in the air, so positioning is more important than your average RPG. Splitting your party into groups that are below or above the enemy team can save you from certain attacks, but they limit your attack options when attempting combos against specific targets. Some enemies are only vulnerable to certain attacks, so there is a good bit of thought into where you attack from and with what abilities since many abilities can affect groups across the different attack planes. There is also a "gotta collect them all" thing going on with the skills system. To learn more skills, and increase your options in combat, you have to "eat" enemies to learn their abilities in a grid system, sort of like FF's Sphere Grid. Leveling will increase your stats, but these "cores" come with a bevy of stats boosts, Passive Buffs, and unique abilities you need to increase every character's versatility. So you wanna have every character eat as many cores as possible to pick up as many buffs and new abilities as possible. Fights feel more entertaining when every new creature presents a new opportunity to eat a new core. The rest of the game is pretty typical anime JRPG schlock and the production values are pretty poor, so this is no Tales or Ys game. The combat pretty much does all the heavy lifting. Thankfully, there are options to speed up how quickly you get through cutscenes. I put a 4, but it's more of a 3.5.