There is a bug that doesn't let me talk to the NPC and upgrade. I accidentally click the new game instead of continue and manage to reach sewers on first try. it glitched out the dialogue box of the NPC's even played the game whole through tried to reset the app still can't talk with the npc. when i try to talk to the npc it just lags for a half second. so i played a new game again :V..
Btw Awesome game will definitely play it over and over.