You can download the final release of Dune II from [link]
RCI did great work in bringing some popular 90's PC/Amiga titles to the platform. The last native, commercial, release was TEK1608 which is a great game and AFAIK still available from R-Comp (for 26-bit machines). Until the market expands sufficiently to justify developing new home grown RO games, I'd recommend buying a gaming console. I've recently opted for the (ARM inside ) GBA.