Ok so here are the pros and cons for this game in my experience:

Pros:
-In a way, it's a Smash Bros Clone. So good for people who don't own that game
-Great to play with your Steam friends or locally
-Weekly Updates as well as Brawl of the Week every Wednesday
-Many Different Modes (Examples: Bomb Throw and Snowball Fights)
-Maximum of 8 players can fight in one match
-6 free characters to play as every week(Well this is both a pro and a con)
-Unlocking characters is free

Cons:
-Game can get very laggy depending on where you are and how your connection is when playing online
-Just about the entire community is full of salty people who take this game way too seriously(Mainly when playing ranked mode)
-Skins, Taunts, Sidekicks, and Event Chests costs real money(That may only be bad for some of you in some cases)
-Ranking System isn't accurate on Ranked Mode
-Most of the time when playing online you will run into people who will spam the same attack in order to win(They will ONLY use side signature to win and nothing else)
-This con is personal, but the crossovers really went out of hand. Rayman and Rivals of Aether were the only ones I personally thought were fine.
-SALT

Summary:

Brawlhalla is a great game to play with your friends or on free-for-all, but on ranked things can get pretty crazy and dumb depending on who you're up against(because SALTY PEOPLE), but other times people just don't say anything. It can take awhile to unlock characters, but it's worth it if you're willing to play this a lot. You should definitely get this game and tell all of your friends who love Super Smash Bros. I would also advise you to NOT BUY the $20 character pack because then it ruins a lot of the experience(Valhalla Pack is fine though). Highly recommend using controller, but I've met some people that can pull of the game using keyboard so choose what works best for you.

EDIT: When dash was first introduced, I hated it at first. It takes awhile to get used to but eventually you get the hang of it(you won't have to worry about this if you're new to this game though). It doesn't really change the whole spam tactic though.

The Tutorial is useless, but you get some start-out money.

UPDATE: After hours of experience in playing this game, I can't even play Free-For-All or Friendly 2v2 anymore. Most of the players either spam the hell out of the same moves(beginners) or insult the hell out of you because you couldn't beat them. If you're lucky, you'll find someone who is nice. All I know is that I can no longer play this game anymore. The community ruined it for me. So play at your own risk.