Good news, its possible to downoland inishie dungeon and play it but its seems complicaded.
Instruction is in japanese here うごかす方法 - Inishie Dungeon Analysis Wiki*
Process of instalation here イニシエダンジョン(クローン版)導入方法を簡単に説明するためだけの動画
I don't have time to check it at this time but good luck!