v0.97

1. Achievements is availabled!
2. "Advanced Mode" is renamed to "Hero Mode". In Hero Mode, you can select hero in each age to release powerful skills;
3. There are now four game difficulties to choose, with massive adjustments to the values;
4. Fixed the bug that main menu items block each other;
5. Fixed the bug that the new blocks may replace the original blocks;
6. Fixed various bugs;