i like your idea for this game but here are suggestions
1. Make tanks look more rugged and realistic looking, same with the environment
2. Make this project WW2 or vietnam themed include scenarios based on real events, there are no ww2 or vietnam era based genesis games, this would be a good example to take advantage of that, make levels based on things like battle of the buldge (Snow) battle of Algiers or egypt (Desert) etc, make the environment have not only tanks but ground troops, different types of weapons that enemies can stop you with, mortars, bombs, bunkers etc
3. If multiplayer can be a thing, find a way to integrate the 4 way play adapter, another crazy idea is to somehow integrate two 4 way play adapters and have 8 players on screen
4. Have an option to upgrade tanks, or buy new tanks