I saw with block 10,000 the difficulty increased by 300%
ACH is said to have little changes from BTG mainly starting from height 0
Coin specs show Difficulty adjusts with every block so going back to review ACH roadmap I find in its Financial Strategy "the first blocks will
have a reduced difficulty level that will allow the development team to mine these blocks very
rapidly, and then the new difficulty adjustment algorithm will kick in.."

Have not studied the source code in detail to see how it actually differs from BTG but I may do so when I have some time later