Nine Parchments

This is a really fun, approachable couch co-op twin-stick shooter. It has a fun theme and lots of collectable items, upgradable skills, and unlockable characters, that encourages replaying earlier levels. It has rock-paper-scissor game mechanics that encourages the team to work together when fighting monsters, and it is fairly forgiving when players screw up. We have had a lot of laughs with this one, and it feels like we accomplished something, even when we only managed to unlock a hat of stun-resistance.

perfect game for a chill session with friends (with lots of replayability too!)
can just throw them a controller and everyone will be able to pick up right away. no learning/teaching needed which is great for when your friends are too stupid to use technology! xD

Scratches the Magicka itch and has a fun campaign to do with friends! The progression system for unlocking character variants is cool as well.

Getting it on sale is more worth your while, and lets you buy 4 copies for your friends without hurting the wallet too much

It's simple and fun. I throw fireball at my friend, and she zap me with her lightning instead of fighting enemies. Then we yell at each other

Insanely underrated game. It plays a *bit* like Magicka, but instead of building your own spells, you get to choose from a random selection at various points (in a similar fashion as Hades boons, for instance).
It's very fun, it's beautiful (of course, it's in the Trine universe), and the characters are absolutely charming.
This game deserves more love.

A game where you go to throw a perfectly aimed Frost Bomb... Only to freeze yourself and your partner. Gauging distance is a must.
When one is surrounded by multiple enemies... One shall use every available spell to take 'em down. In the end your co-op buddy is so engrossed in smacking enemies... That he doesn't realize that he managed to kill you as well. Ensure that you remember that you aren't alone and that your partner is somewhere... Amidst all the chaos...
In certain areas, you might be doing well... Constantly moving and keeping enemies at bay... Only for your foot to slip and you end up falling backwards into a crevice that blended in rather well with the background... Leaving your partner to deal with a horde of mobs. Watch your surroundings! They aren't always to your advantage.
There are so many more accidents... So many other things that may happen... Not all bad. Sometimes they are happy accidents. But that's for you to figure out... If you so choose to play the game. :3
After exploding enemies, including your own face with a giant fireball or zapping/stunning the sheet out of your partner when all he is trying to do is put an end to that one annoying Boss... You are bound to learn a thing or two, and become a far better player.
As for the rest... Hijinx ensue in real life as well...!

Amazingly good local-coop game! The people of Trine know how to make a good game!!! Get 4 friends you want to campaign with, and just buy it. Full price, half price.. it's worth it.