Thanks for this In depth review and suggestions. This really meant a lot. Stars spawn after every 50 seconds so there will be a bug that more stars not spawning.
Speed Up and Down stopped working may be another bug :p
First 2 gameplay suggestions I also thought about these but was short on time so. I will implement those in Future.
last 2 suggestions are so good. I will definetely implement those.
Music added at the last. I didnot find anything else :p :)
Thanks again. :)