Season 2 of a series, regardless of its genre, should be reserved for a series that was highly successful and popular in its first season because of a memorable plot/storyline, solid acting, or good writing and directing, that left everyone wanting more.
Sadly, most of the series that have gotten a second season lately, especially Thai BLs, have been utterly disappointing (see for example "Love by Chance 2", "Tharn-Type season 2", "Love Area season 2", among others) as they couldn't overcome a myriad of flaws and some questionable acting and directing that left us viewers regretting our decision to watch.
Gen Y season 2 is NO exception despite what one reviewer (who has only watched 4 episodes) said about this being a wonderful show. It is NOT... Gen Y2 became 12 episodes of dull acting, bad directing, many storyline plots that were even more boring to watch and useless situations that were dealt with in usual BL fashion of not being dealt with at all. Here's why.

The storyline/plot:
This story seems to follow the concept of the original "2Moons" with Wayu (instead of Wayo), Kit and Pha remaining constants from that show and with virtually identical characters. The idea of having Wayu and Thanu as the main couple in season 2 was created by the plot of Pha leaving Wayu alone in season 1 and telling Thanu to take care of Wayu. It took all of season 1 and then nearly a third of season 2 to finally know that Pha is sick (I believe he had a sort of brain tumor judging by what Kit is reading while doing research on the disease) and is dying, so he leaves Wayu because he doesn't want him to see him like that. Really?! The love of your life and you just leave one day, ask another guy to "take care" of Wayu for you, and vanish into thin air without an explanation? So this was sinkhole #1 in the plot.

Then Kit and Mark have their own issues... the cat and mouse game Kit plays in season 1 by rejecting Mark's advances and flirting until he finally breaks his walls and accepts that he likes Mark, shift into Mark and Kit having a dull relationship (in my opinion) with Mark acting cute all the time because of how much he loves Kit and the other trying to restrain himself and control Mark's personality at the same time. And then, they drift apart when Kit applies for a scholarship abroad (one of the usual Thai BL clichés) and decides is better to take some time apart from seeing Mark to make sure both get used to living apart from each other. Really?! If I knew I was leaving to study abroad, I would have spent every single second I could possibly spend with my loved one before I had to leave, not the opposite... Kit is basically training Mark (and himself) to be alone in case he leaves but both spend countless episodes crying and sighing because they miss each other. So this was sinkhole #2.

Pha reappears early in this season but is to reveal he is dying. This takes Kit on a quest to save him, trying to apply for an experimental study in the US, neglecting Mark and almost everything else to save Pha. Thanu feels sad about his friend and also a bit guilty by "keeping" Wayu. And Wayu has no clue of what is happening at first, until Sandee (more on him later) reveals the truth, making Wayu feel guilty about being mad at Pha for what he thought was just Pha breaking up with him and then compensating by staying with Pha all the time at the hospital, feeling a bit angry because nobody told him about Pha's health, and then guilty again for having feelings for Thanu while Pha is dying. We had to watch nearly entire episodes of these scenarios I mentioned above and they became quite boring after a while as nothing was developing with the other couples and Wayu-Thanu-Pha kept this love triangle from dying out. Finally, Pha does end up dying (in a poorly edited scene with Pha's mother saying "he is gone", but then Wayu, Kit and Thanu going in the room to find he is actually alive, before he finally dies) which released us from watching Wayu suffer because he loves Thanu but wants to take care of Pha. So this was sinkhole #3.

Sandee is the bad guy (I guess) of this season as he tries to "fix" the couples to what he thinks is best. Thanu with Phai and then also messing with the Tong-Pok couple because Tong switched his grade with Pok's so he could be accepted in the university. Ok, I get you're angry at Tong because your grade was switched... but when Sandee confesses to Phai about what he did and then in episode 12 when he talks to Pok, he reveals the switch didn't affect either of them as the grades were identical. Really?! You went through all the mess of threatening and blackmailing Tong, being outcasted by your group of friends, having Pok beat you up a little, and for what? In the end the switch didn't make a difference! And then trying to put Thanu and Phai together serves no purpose in the series as Phai already made it clear he will not interfere in the Thanu-Wayu relationship, so what... Sandee likes Phai? Maybe... Sandee just wants to play matchmaker due to his distorted idea of what love should be (all the fate-destiny crap he and Phai talked about since season 1) Maybe... but we never know for sure. So this was sinkhole #4.

Pok and Tong have an almost toxic relationship with Tong refusing to kiss as he is "saving that for his real love"... great... but his conservative nearly puritan perspective goes to hell when both are being fuckbuddies and doing nearly everything (including the shower scene before they break up) but with Tong still refusing to kiss. They lack communication, they let Sandee influence them quite easily, they never listen to the rest of their friends and then all is solved in episodes 11 and 12 when they each find out the truth (from someone else), Sandee apologizes, and all is well in the world of Pok and Tong. So this was sinkhole #5.

Then we have the secondary characters who have nothing to do. Jack and Ko could have been the best side couple of this season as the actors worked together as a couple in "My Mate Match" but they barely get screen time with all the characters in this series. At least they have a decent and cute ending... We also have the mystery that Padbok was in this show. He was constantly fighting with Thanu in season 1 for what he thought was his friend's betrayal... but then he disappears in season 2 with the excuse of him taking care of his sick father. He briefly appears in the waste of episode when the whole cast dresses up for the mini-plays but leaves after literally 10 seconds when he sees that Thanu will be involved in the scene as well. Then in episode 12 he listens to Thanu and Wayu, then Jack and Jew confirm the story and what could have been solved in about 2 minutes of the show, ended up being solved until the last 10 minutes of the season. Not sure if Junior (the actor who played Padbok) was busy with the new BL he will lead (something called "Boxer in Heart" where he will play the main couple along with Tiger from "My Engineer" and "Top Secret Together") but his absence in this season was made even more evident by the choppy scenes he had to film to solve his problems with Thanu. The rest of the characters either play matchmakers or provide some sort of comedic relief but they barely add anything to the story. Phai more or less gives some good advice to Kit in a few episodes but nothing that good. So this was sinkhole #6.

The acting:
Sadly, most of the actors, while attractive, have fallen in the same sort of roles. Bas (playing Wayu) is stuck with the suffering damsel in distress character that needs a big strong man like Pha or Thanu to help him and all his characters have that similar feeling. Kimmon (playing Mark) and Copter (playing Kit) have fallen in the playful/flirty character (Mark) and the serious, uptight, centered character (Kit). Bank (playing Sandee) and Pon (playing Phai) were nothing like their characters from "The Moment" and "The Moment Since" where they had some soul and personality, here both were quite dull. Big (playing Pha) had mostly bed-ridden scenes in the hospital and maybe he was also focusing on his support role in "Something in My Room" (where he doesn't appear much either and his character is quite weird) but his scenes playing a sick man were forgettable. The other Bank (playing Pok) and Bonus (playing Tong) could have used some acting directions as they had some of the most intense scenes, whether having sex or arguing, in the series, but they didn't convince me much. The rest were just there.

In the end, Gen Y 2 ended up being another disappointment in what is becoming a long list of disappointments now, as companies are just producing BLs because they see them as profitable or trendy but don't bother too much in terms of quality. So, yeah, avoid this season if you can.