I have been trying this game for a while now. The progress is way to slow. The gold bricks do not help enough in my opinion.
The highest floor I have gotten to is the 8th floor and it slows down. It even doesn't make sense to prestige since you barely get any golden bricks. Too many bottle necks built into the game. I kept hoping for more updates to address the balance issues.
the ruby boost is nice, but has a drastic slow down near the end of trying to max skills or stats.It feels like the early game is too quick, with an exponential increase in time, with no ways around it.
The prestige system also has a slow down. It would be nice to be able to use these points to boost base skills or speed up stat growth. As of now, the wall has been hit and it makes it almost not worth the hassle of a restart.
I have not even finished the second ending, but am near legendary in every skill. Stats have a VERY slow growth from levels 40-50.
An option to hide completed quests. When you only have one left, it can get very tedious to have to keep scrolling back down.
Similarly, the achievement system would be nice to allow hiding maxed ones.
Over all, I think this game has great potential and could use some extra endings or variety in choices. For instance, becoming the cook gives you a profit and ability boost for the select skills.
I must agree with several previous comments on the issue of the early wall.
I have been heavily upgrading the speed, but now need to wait 4 hours for another .2 max speed. Even with LP, you only get 1% more.
I can understand not wanting to over power the game early, but I am also having to wait 20 hours to Legendary Prestige (which seems to be the only way to drastically speed up.
With one Worthy Prestige, I can make it so it is completely passive (aside from Chests) and it is now too slow. I understand it is an Idle game, but when there is nothing else to do and no real strategy aside from waiting, it will not promote longevity.
For a game called Light Speed Runner, it is taking too long to gain any speed
 "Babel Tower"){kind=icon}
 "Idle Quest"){kind=icon}
 "Light Speed Runner"){kind=icon}
 "Mighty Party"){kind=icon}
 "SkillQuest 2"){kind=icon}
 "Realm Grinder"){kind=icon}