4/5 solely because of iffy controls. SOOOO many times I jumped once and watched the double jump bird disappear. It just registers double taps like 50% of the time, making the game frustratingly hard. The wall jump doesn't seem to always work either, but I am prob just sucking/frustrated.
The grenades need some sort of fuse or more friction, it's aggravating missing a target by microns then watching the grenade roll across the entire level.