Fun game with lots of challenges. I can play this game and not spend any money to keep going. Energy replenished with time, you control the time it takes to get full energy. The game hasn't crashed, stuttered or lost my accomplishments. Game is fun for any age group. I'm over 70 and no problems following quests. Having lots of fun and recommend this one for anyone who likes a challenge without needing to keep waiting for energy to continue.