I felt like I wanted to share my thoughts on the new Star Guardian Gamemode here, so well, here they are! NOTE: I usually play onslaught, so these thoughts are based upon that.
**Comparison to other Featured Gamemodes:**
I feel like this has got to be one of the most unique featured gamemodes out there. While URF, One for All, Ascension, etc. do all bring their unique aspect to the game, I don't feel that extra 'oompf' after playing them a ton. They're fun to play for an evening, maybe two or three but after that they start to get stale. With the SG mode I haven't reached that point yet however!
Also, toxicity is something you don't get around in the other gamemodes (yes, even in URF people still flame each other for w/e reason). I have yet to experience a toxic person (this excludes salty people of course) in this gamemode!
The roster is pretty, interesting. You are somehow required to pick one or two utility champions (as they're categorised) in order to not get utterly destroyed. However, I feel like poppy being the only tank is a bit of a shame. I like playing tankier champions (yes, those people do exist) and the only reasonable tanky champion is poppy. (I understand that this has to do with the fact that only SG-skins can be played in this mode). Janna and soraka are pretty strong here with ardent censor and the peel they can provide, and they're fun to play. Soraka E is especially strong against the kog-maws, as it prevents them from charging up!
On to the mages. I feel like they are the least fun to play in this mode. Half of the time I'm waiting for my cooldowns (especially in the earlier levels/stages when I don't have cdr yet) and just walking around doing nothing. I have yet to see a lux perform well with her little mobility as well. I haven't seen enough syndras though to be able to determine how good (or bad) she actually is. Her ult is pretty lacklustre though, as single target nukes don't really do that well here.
Adcs/marksmen are something different. I feel like jinx is so strong here, with her pretty much permanent movement speed steroid and rocket form to get rid of those annoying malzahar voidlings that he somehow got into this game. MF's ult can shred entire spawn groups and her W allows her to kite more easily. The malzahar voidlings also provide a free crit-proc on the next thing they hit, which is pretty good.
Ezreal on the other hand feels, well, weak compared to MF and Jinx. His Q usually gets blocked by those voidlings, which is one of his main sources of damage. He does have a gapcloser though, which helps out a bit.
Oh boy do I love the enemies that were implemented. They take one or two key elements from an existing champion in the game and are based around that. Vel'koz barrages you with his constant Q, and the bigger variant has his laser beam. Kog'maw charges up, and once charged up deals tons of damage while being relatively squishy. Skarner peels for his fellow enemies with his ultimate, and rek'sai uses her tunnels to knock the star guardians up. Cho is the tankiest of them all, while providing the necessary cc for those near him (once he gets to them as he's super slow). The big cho also noms people, dealing damage over time to them until they are killed. Pretty strong, but seeing all the remaining 4 star guardians team up to kill him asap to save their friend is such a beautiful sight. The voidlings don't seem to do much, but once enough gather they can easily take you down. Don't underestimate them!
All in all they're all pretty balanced, though some are stronger than others, and provide some great interactions with each other to provide tough challenges.
Most levels are set up in such a way that you must cooperate in order to pass. If you don't, I.e. you split up, you're probably gonna lose. Slow and steady is the key element. In the final level, defeating the rift herald thing provides quite a challenge. Her syndra ball spin to win thing instantly kills you if you hit too many of them (as long as you're not playing poppy) so hide behind the walls to dodge them. Movement speed (MF, jinx, Ahri) and/or gapclosers (Ezreal, Ahri) is key here. It's pretty difficult, though not impossible, and when you do finally win you feel sooooo good.
There's however this one semifinal level which is... probably even more difficult than the final level. It's the one with the moving area and the vel'koz's and skarners. It's pretty easy at the start (assuming you kill all 4-8 vel's at the start) but gets super hectic near the end, where multiple skarners spawn at the same time and where the giant velkoz starts shooting his laser at you as well. Dodging all of the vel's Q's is pretty difficult in itself already, but having 5 newly spawned skarners walk up to you and cc-chaining you into the Q's and out of the zone makes it outright feel impossible (and unfair!). You can be a jukegod, but if you get cc-chained you're done for.
Fun gamemode, Stays fun. Little to no toxicity (though you do encounter some salt sometimes). Decently balance guardians, though some are definitely stronger than others. Unique enemies, and a good final boss level. One level feels a bit overwhelming and unfair though.
I'd rate this gamemode a whopping 9/10! (no 10/10 because we don't have Star Guardian Urgot as a playable character or final boss!)