Level 20 for those that don't get it: The zombies with the items start running towards the gate places, they open when the zombies with the items reach them.
Greying out the currencies while you are in a shop to spend them is not very helpful. I don't just want to know if I can afford something, but how much I will have left too.
The pacing is just so weird at some times. Why have a Low quest thats basically "reach level 36"? Why have the 3rd boss challenge locked behind a level requirement that's so high you are at 20k in the survival challenge? Why does the survival feel so... boring and slow for the most part and insanely overwehling graphically?
Just spent 250 marbles by accidentaly clicking a button while hecticly trying to get the next "ascend very fast" like achivement using the experiments. Hey game, no i didnt want to "instantly finish" a single experiment. This really should have a confirmation button. And I wouldn't be as mad if "finish all your experiments" wouldn't be the most useless way to spend the marbles.
As you want to improve I try to give some constructive criticism. The sound: I mostly get "scrt creech" sound, that sounds like a clutch being killed over and over again by the driver. It's horrible to listen and I stopped the game simply because of the sound, otherwise I would have run it for a while to see if the driver gets better.
The driver should be driving on the road in the beginning. Maybe on better speeds/acceleration fail to keep on the road, but watching someone scratching the wall while going around 5km/h is annoying.
Unfortunately it didn't safe on my first try, my firefox crashed while trying to shut down, so I dont know why it wouldn't save. Something else: It would be nice to receive idle gains while in the upgrade menu!
I liked the massive cascading of the bumper poppers on higher percentage, it made my last restart to get the 100 upgrades/100k bumpers much more fun. Now upgrades between 50-100% feel like just wasting your points to sometimes getting a seconds bumper.
The tutorial feels awfully slow. It's just my preference, but I'd like chat windows I can click away and through instead of watching videos I can't speed up or jump.
 "A Grim Chase"){kind=icon}
 "Idle Quest"){kind=icon}
 "Idle Harvest"){kind=icon}
 "Overlord's New Mansion"){kind=icon}
 "Cyber Chaser"){kind=icon}
 "Cosmos Quest: The Origin"){kind=icon}
 "Dogs Vs Homework"){kind=icon}
 "Cave Heroes"){kind=icon}
 "Shonen Idle"){kind=icon}
 "Transport Defender"){kind=icon}
 "Idle Racer"){kind=icon}
 "Idle Programmer"){kind=icon}
 "Mario Pond Challenge"){kind=icon}
 "Idle Potato"){kind=icon}
 "PlinkyPlinky!"){kind=icon}
 "Swarm Simulator"){kind=icon}
 "Cat Clicker"){kind=icon}
 "Run!"){kind=icon}
 "Imperator - For Rome!"){kind=icon}
You can now press M to mute the sound, and the driver is now better off from the start, so he can stay on the road for longer.