I purchased it this morning. For anyone interested, it runs well on the MiSTer Genesis core.
A couple things the game could benefit from, improvement-wise, would be a saved high score table, a visible counter for flags that the player misses, total distance covered being displayed somewhere, and something to reward the player when they have collected enough flags for a 1-up but already have max lives.
I look forward to seeing what else you may produce in the future!