I buy off gog.
Here's Terra Nova SFC on the house
https://www.mediafire.com/file/u84f8xgfy10c3hr/setup_terra_nova_strike_force_centauri_1.08_(28045).exe/file
>>714417190
The best mech game imo is Heavy Gear 2 but MechWarrior and Titanfall are also really good. Also Armored Core and Front Mission if you emulate