Linking Harvest Moon DS with FoMT / MFoMT (GBA)? Impossible—No Cross-Platform Link

Impossible. No cross-platform link exists between DS and GBA games.

Why

• Different hardware (ARM9+ARM7 vs ARM7 only).
• Different save formats (NAND vs SRAM/Flash on cart).
• No link cable / wireless protocol between DS slot-1 and GBA slot-2 for data transfer (only GBA game boot).

What DS *Can* Do with GBA Slot

• Boot GBA games (DS/DS Lite only).
• Pal Park (Gen 4 Pokémon) — transfer from GBA cart to DS game.
• Some games unlock extras if specific GBA cart inserted (e.g., Advance Wars DS + AW2), but Harvest Moon DS does not support this.

Enjoy Separately

• FoMT / MFoMT (GBA): Best 2D HM, deep marriage, mining, festivals.
• Harvest Moon DS: Touchscreen tools, larger map, mineral town cameos, but buggy (save corruption glitch).
• Harvest Moon DS Cute (Japan/US): Play as girl, different bachelors.

Each stands alone as a complete experience.