Heroes of the Storm is a MOBA created by Blizzard Entertainment.
Pro Easy to learn
Heroes of the Storm was created to be a streamlined, modern take on a MOBA, something that many others have aimed for but HotS succeeds in. Shared XP keeps teams leveling together; No Last Hits means that everyone gets XP from minions and puts less importance on who gets the kill, since there is no Carry-player. Choosing talents instead of having to buy items gives the game complexity without forcing players to wade through menus and travel back to base. The game still offers a challenge to master at higher levels, but is more accessible to new players.
Pro It's always possible to make a comeback
Even if you are in trouble because you lost almost all the game, you can still win by killing the enemy team on a stupid move they made at the end of the game. And it's never unfair: it's always because the losing team was overconfident and the winning one was the focus.
Has a relatively smaller playerbase than other MOBAs and Blizzard games, but one that comes from fans of every franchise represented in HotS, whether it be WC3 or Starcraft, leading to a wide range of players of all ages familiar with raiding in WoW, or the micromanagement in Starcraft. Regardless, many HotS players will share a common love for at some Blizzard franchises. All chat is disabled outside of Custom games, which arguably leads to less toxicity, as well as the fast paced nature and shorter match time which means less time for trivial flame wars as well as no surrender option and many comeback mechanics, as well as very little last hitting or kill stealing to be had leads to a far more relaxed environment.
Pro Hero and playstyle diversity
Blizzard has gone above and beyond to introduce Heroes that break the standard molds for Tanks/Support/Damage characters. The talent system allows for diversity in how a character plays. Some heroes can even talent into multiple roles, like Varian, who can become either an assassin or a tank. Each Hero has 2 Heroic Abilities (Ultimates) to choose between, providing even more diversity in how each character can be played. Also, Blizzard has introduced several highly unconventional heroes, from The Lost Vikings, who are three separate characters controlled by one player, to Cho'Gall, who is two different players controlling one character, to Abathur, who doesn't venture out into the battlefield himself but manipulates the map and assists teammates from afar.
Pro Fun emotes from heroes upon team work and team kills and more
If you play Nova and Kill Vala, Nova will say "HUNTER!?!? more like Hunted!!"
Or if you play support and heal Raynor he will say "This medic is my new best friend".
These emotes make it very clear what happened, and add a dimension of fun that you don't see in other MOBAs.
Also, you can hear some emotes after other events, like your own hero death/respawn or during starting second of the match.
Pro No last hitting, no gold, no items
The game does away with the shop mechanic entirely. No last hitting means players don't have to focus on a minigame for the first 20 minutes so they can jump into the action much faster. No shop means that supports aren't starved for cash and can remain strong and relevant throughout the game. No items allows for the hero-specific talent system to shine, which provides a much more unique and easily balanced way to enhance your character.
Pro Deep but not complex
The game removes a lot of pointless features of other games like last hitting and out-of-game rune/card buffs. It's also much clearer, with natural percentage based increases for characters rather than "armor/intelligence" stat increases. It also has a large map pool with greatly differing objectives in each one forcing you to consider how your playstyle will adapt to the opponent and the map itself. It may appear to be simple, but there is a lot of hidden depth.
Pro 1st Esport broadcast on live network television
While other esports have aired on ESPN 3, Heroes of the Storm was the first video game broadcast live on Network TV on ESPN 2. Blizzard hosted the Heroes of the Dorm tournament, also one of the first college esports events, in which college teams played for the prize of full college tuition.
Con Can feel difficult to make an impact as a solo player
Since Heroes was designed to be more team-centric rather than individual players carrying games, games can often feel beyond your control. For example, ranked games can often feel like a coin flip of which side gets lucky and avoids players prone to tilting or toxicity.
Con Great for a while, but lacks strategic depth
The basic concept of pitting two teams of five players against each other is good for a long while, but once you get your bearings and know where you belong in team-fights, you start noticing that the game has no depth beyond a single match. There are no campaigns or big picture to be won. It's just you and that match, which you can influence only so far.
Con Lower playerbase game knowledge
The average Heroes of the Storm player is less informed about the mechanics and basic strategies of the game compared to the average player of other MOBA games. This is due to a variety of reasons, like the popularity of Quick Match and the relative lack of learning resources both in-game and out because the game isn't like other mobas so people bring the wrong knowledge and expectations to this game.
Con Lack of good talent diversity
Compared to the flexibility of an item system, the talent system limits the number of ways you can build a hero. The talent system is often structured so that there are 1-2 primary builds which usually focus on empowering one of the heroes basic abilities, and then a handful of niche talents. This causes a hero to feel very much the same every time you play it.
Con Increasing number of CC effects
If you played or used to play World of Warcraft, then all the disabling effects are familiar to you -and how the standard practise is to chain them for guaranteed kills. Blizzard has brought this to HOTS, so be prepared to be deleted no matter what you do.
Con Matchmaking and ranked trouble
HOTS is a 5v5 game, so you will lose many matches due to reasons out of your control. This makes the ranked and matchmaker a feel of gambling, where you have no chance to influence who you are matched with. Often one side stomps the other and when it happens, you have little control over it.
Con Reconnect system
It's extraordinarily difficult and frustrating to reconnect to a game in Heroes if you disconnect for any reason. Reconnecting players can't simply "pick up where they left off", they have to simulate everything that has happened in the game between the moment they disconnected and the present time, which causes the reconnecting process to be extra slow and occasionally impossible.
Con Slow fights
Heroes inflict little damage to each other, which has the potential to make fights seem long. On top of this when one falls behind many of their skills will become useless making for a fight that one is delegated to a support role, which will also add to the slow feeling of a fight.
Con Badly designed and unbalanced game mechanics
The whole game mechanics are terrible: the fact there's no in-game currency ironically make the game heavily focused on farming (due to levels being an extremely important factor to win battles), there are no strategies you can use since objectives have a big impact on the game, so basically you end up just repeating cycles of farming/objective. Last but not least, the game balance is horrible, since skills were directly based on Blizzard's universe and without any adjustments to make characters unique or to create synergies with other characters or specific strategies. It's basically an oversimplified version of every MOBA out there.
Con Terrible matchmaking
In any of the matchmaking queues, the chance of being put against someone with much higher skill than yourself is very high. The ranking system goes in this order: Bronze, Silver, Gold, Platinum, Diamond, Master, Grandmaster. On multiple occasions, silver players have been placed against an entire team of Grandmasters with bronze allies, leading to very poor experience.