Brawlhalla

Any game type played online counts towards this achievement -whether that be ranked, friendly or brawl of the week. So in progressing towards this, you can get Our Powers Combined; Let's Do This Again Next Week; Calm Before The Storm; Four's A Party; Welcome To Brawhalla for a total of twelve matches played plus also 'Til KO Do Us Part if you have a friend plus also progression/possible completion towards a number of other achievements

This popped at around the same time as my first legend (Not an Axe-ident) and account level 10Just One More Game! for those looking to budget their time.

You need to get to the end of each match for it to count (I believe) and the practice rounds against the bots don't count towards the total
But you don't need to play as the same character in the 30 games either so you can switch as needed (for daily missions or just some variety ...)