Just throwing it out there, but I think achievements could spice things up in this game!
Roster a new character! XP for you!
Use three self healers in a single match! Health pack for you!
Max Champ a 5* - LT and a lifetime supply of Cheetos for you!
Get Phoenix Cascaded to Death! - Heroic Token for you!
Contact Customer Service - No soup for you!
Complete the Prologue - 5,000 iso for you!
Suggestions appreciated for other cheevos!
We need a flawless victory award:
Just throwing it out there, but this is already a thing. 
In response to the OP
Any player who subscribes to V.I.P for four consecutive months can choose any cover they want at the end of month four.
That means in a 12 month period players get to choose 3 specific covers they want.
At the end of months four, eight and twelve, a vault opens showing every single cover available.
It’s open for approximately 5 days.
You chose a cover you don’t have or that cover you’ve been waiting patiently forever but it won’t drop.
In the same vault you have 1000HP and 50,000 ISO-8
Watch the V.I.P subscriptions sky rocket.
Edit:- Of course it should be backdated
Wow. For a post that was supposed to be silly, things got awful serious…
Yes, achievements would be really nice, but seriously, you can fund here dozens of better/deeper ideas about them.
F.e. this https://forums.505go.com/discussion/43970 - achievements on daily basis.
I got some ideas:
Fight Juggernaut/Ares more than 10 times in one day - Gain 50 health packs and a donation towards the cost of your psychiatric treatment.
Complete a muscle node while 4 or more enemy strike tiles are active -
Win a fight without using any powers (Passives N/A and Strange barred for obvious reasons) -
Defeat Enemy/Hero with there nemesis -
Tbf there’s endless possibilities but it would definitely help breath something extra into the game think i mentioned achievements on another thread to someone else but damned if i can remember the thread, so even in jest i still think it’s a good idea in general regardless lol
I understand the tone of this thread is lighthearted, but I’m kind of burnt out on achievements. Nearly every game has them now and more and more what the player is ‘achieving’ is just random, silly stuff oftentimes completely beyond the control or skill of the player. I view SCL and Daily resupply as achievements of sorts, with nice rewards. I don’t really need to know that I’ve downed Juggernaut for the 100,000th time to prove my dedication.
Then again… I guess I wouldn’t argue against another source of rewards.
I’ve always thought there needs to be more for alliances to try and accomplish together so maybe something like ‘Alliance Accomplishments’ would be cool. Like, if you reach a certain score in Civil War anyone who is active in your alliance will be able to carry 11 health packs instead of 10. Or maybe after your alliance reaches so many top 100 placements they get a recruit token, which can then be achieved again.
I’d like a nice reward whenever I get one of those elusive Match-7’s.
I always stop and admire for a second when one works out. I think it should create a super-crit tile.
Does the game still have the couple of achievements that were (I believe) specific to Google Play Games?
I realize that is not the same thing as SCL XP as in these suggestions, but could be a baseline to implement.
I would like each character to have some sort of challenge to them. Something cumulative over time and something for a one game achievement. Something like buff an attack tile to over 5000 for prof x, or use get murderous aim’s conditional extra damage. Might be tough to come up with relevant challenges for each character tho.
Or maybe they can be tied to your team, like use a team of all guardians of the galaxy, take down Doctor Doom using Squirrel Girl . Then cumulative achievements like use a character 1000 times or something. It might get people to actually use some characters. As for the rewards, probably just some iso. Enough incentive to try to get it but not game changing.
I think there should be an achievement reward every time someone hits Da chosen one or Jamie.
100% on this, I also hate achievements that basically just amount to “play the game.” Like, you’re giving me something called an “achievement” for finishing the tutorial? Really dude?
I don’t mind achievements conceptually, but I’m already hooked enough trying to roster and level everyone without shooting for goofy little side goals on top. No thanks.
I’ve touched on achievements before and I think with all of these characters it would be a great game mode with unlimited options. The rewards could be small for easier challenges and big for harder ones. And if some could be done casually instead of under time constraints that would be welcome as well.
It would make the game more puzzley (like DDQ4), which would be a nice break from the repetition, could force you to use characters you rarely if ever use, and could make you play the game in a unique way.
This is actually already a Googeplay achievement.