Visually, it appears like the dragon is going to hit like 50% of the obstacles because you can't move "enough" left/right. Controls are what they are, plenty of other comments on that. Would have liked a skip button at the end.
Bit unclear how to unlock items. To new players: you unlock them in fountain with gems. There are no dupes and the price is 100/item (use 1000 to unlock 10 at once). You need 18,100 gems total. See progress in stats. Progress is saved, no need to worry about disconnect.
Btw took me like four 3900 score attempts to finally break 4000.