READ IF YOU'VE NEVER PLAYED BEFORE
Heartbender is a mod comprised of many different items to shake up your survival experience, for example, ever wanted some armor before getting iron, and without resorting to leather armor, well we've got wooden armor for each and every type of wood in this version of minecraft, so you'll never get a bad spawn ever again! You'll never be killed by skeletons before you've even gotten your things together. Wood armor is nice and all, but you can't craft everything out of wood...or can you? With the Flimsy shears, you can grab yourself a bow before the sun sets...or you could craft a fishing rod I guess, but one problem, those shears require a new, renewable source of string, Flimsy string (you know the stuff from the "No Tree Cutting" mod? Yep, that's what it is), which can be crafted using 9 wheat seeds or 3 leaves of any type, making it much easier to get than regular string. These things aren't even the last of the quick to obtain items, like Copper, an ore you've probably seen and used before but hey, every copper tool is different from mod to mod, and this is no exception, for the armor can be charged using the power of lightning! Maybe there's a way to do that without a trident, or luck. Once you've gotten some iron, you're not done with this mod yet, for you can craft yourself a gun...with no ammo, which is decently expensive to create, but as it is in fact, a gun, it's quite powerful, especially as a ranged weapon, it even has it's own, separate fusions with other items from this mod, like primed tnt, which...actually is more destructive than regular tnt, and isn't affected by gravity at all, and of course, is prime to explode, but with that tnt, (and a smithing table) you can create a explosive projectie without having to install draconic, the only downside if the fact that, unlike the base gun, it cannot be equipped with attachments, which enhance the audio, and visuals of the gun, as well as it's actual combat properties. Gold is notoriously horrendous for it's 32 durability points, and it's not much different here, but gold here can be used to craft ammo, the only way to use your gun. Most of these things are nice to have, but there's a material you can craft called the pole, used to craft two things, the heartpiercers, a weapon set that deals constant damage if the target has no chest armor, if they do, it will deal extra damage to it instead, but the pole can also craft the staffs, used to make magic weapons of different effects, one of which being a fire staff, which unsurprisingly lights targets on fire, and blocks. Enough of the early game, lets get late, with 10 diamond blocks, and a Charged diamond, gotten from mining Charged diamond ore with diamond or above, you can enter a new dimension, filled with a biome for each dimension, including this one, it's also infested with quite a few strong enemies to make your way to another late game ore even harder. This new ore is the ruby, the most powerful material in this mod, which also lets you craft the item to fight the boss of this mod, which will be quite tough to beat.
OTHER STUFF
Commands:
Aside from all of that, you can use a special command that doesn't require cheats to lock yourself into a somewhat cheaty mode, but the way to unlock that command must be following LowTierGod's advice, unless you're in hardcore, then have fun getting that command
There's also some actually cheaty commands that being /heal, which fully heals you, and fully fills your hunger bar, and /ignite, which...just sets you on fire.
Random Loot:
Along the way you may encounter special loot from mobs, these being lootbags, lootbags, added in 1.1, were the replacement for a duplication bug in the game, they can be dropped from any mob, with a varying chance, this can be increased with looting of course. Lootbags have a variety of different items inside, but you'll only end up getting one of these many items, it ranges from garbage to godlike weaponry, have fun getting lucky...or not.
But your luck can be increased further using the block added in 1.2, the Lootbag Merger, I think you can guess what it does.
In 1.4 (I know, should of did that in 1.3), another lootbag was added, instead of decreasing the chance for bad items, it upgrades all loot in the bag.
Dummies:
Feeling like testing out your weapons, but you either have too much power, or your friend doesn't want their armor broken, there's a solution, the dummies, a set of 4 different dummies, used to test out your weaponry, without ending a life, the first two are Undead Dummy, and the Regular Dummy, the Undead is susceptible to the smite enchantment. The other two are the same pair, but with the equivalent of full diamond armor, reducing incoming damage, all of these dummies can be killed by right clicking.
Different Effects:
As a mod maker, it's practically necessary to make some different potion effects, however, only two can be brewed, this being Fatal Poison, a poison that can kill you, and is a bit more potent, and Recall, teleporting you to the world spawnpoint, giving you a nice escape from danger...as long as your base is close by
However, adding effects is nice, but an effect has been changed with this mod, this being nausea, which now causes the afflicted entity to randomly change their velocity by a random amount, this means eating a pufferfish is an even worse idea now!
There's even an effect similar to Perish Song, giving you a death timer, and can be sped up if cleared.
Passives, Actives, and Traits:
When finding certain armors, tools, or weapons, you may find one of these three things: Passive, which are indications of an ability that only happens when attacking or using the item. Active, which are right-click abilities that last for a limited time and have a cooldown period, you'll usually find these on higher tier items, and Traits, which are mostly abilities that don't fit the other two types, like holding an item or doing something specific with it, like disabling shields randomly when attacking.
Mobs:
Currently, there are 5 different zombie type mobs in the game, and you'll wish that they weren't so prepared
Zombie Brute: The first ever mob I've made, and he's tough, dealing massive damage to unsuspecting victims, and tanking your hits pretty well, he also has a chance to keep himself from dying, and starting a super phase 2, but this chance is pretty low, but he has a normal half health phase he goes into that switches out his weapon in an attempt to possibly kill you, and if he does, he will actually heal and gain strength briefly, the health gain is actually proportionate to how much health the mob that he killed was, capping out at double the brute's max health
Zombie Archer: These absolute pricks are practically the skeleton's big brother, with fatal poison tipped arrows that he fires off decently quickly, plus, he's immune to all projectiles, so no sniper duel with this zombo. This archer actually has one problem, he's the least geared out of all of the zombies in this mod, meaning he's quick to kill once you're in.
Zombie Wizard: The only neutral zombie you'll encounter, they aren't hostile to you at all, but attack Heartstrikers and Witches using a dispel staff, which removes potion effects from those in the surrounding area but deals no damage.
Zombie Defender: These tanky zombies protect their fellow lads with their shield and high health, their shield prevents them from taking any sort of damage from most weapons...but hey, you know what beats shields right? The Defenders also stick close to nearby Zombie Brutes and Archers and will attack you if you dare come close.
Zombie Lord: The boss to end all zombies. This zombie commands all the lower zombies and protects a difficult advancement for you to find. May gods spare your durability.
There's also the
Heartstrikers: One of the only neutral mobs in this mod at the moment, they spawn with nothing and get their gear after a minute of in game time, and attack most hostile mobs, and reproduce automatically though pretty slowly, and die out after 10 minutes
(Do note that even lovebugs live longer than these gals)
The Four Villager Wizards: You'll encounter these wizards in towers, scattered across the world that house these wizards who are entirely neutral to you, the towers they live in contain a barrel for you to loot for free
(Water, Earth, Fire, Air; Long ago, the four nations lived together, but that all changed when the Players attacked.)
Breaker Blade:
Added in 1.4, this sword deals increasingly more damage, if you can continuously attack your target, it can also disable shield occasionally.
Bottle of Milk and Dispel Staff:
Added in 1.9, These two are used to clear potion effects from those affected, the Bottle o' Milk can be made with any potion (Including water), and a bucket of milk in a brewing stand, though the dispel staff can only be obtained via a Zombie Wizard.