New game needs new game engine

today i have realised that to make a medievil game i must have a game engine built first before i can create the game. so i need people to tell me where i can find the software to build my game.Please let me know.Ciao.

Demo

Today I have started work on a demo as part of my medievil Fangame Project(Who would'nt?). The demo will introduce just some of the controls to people who have never played any form of medievil game before and to those who have.The demo will be based in a graveyard and I already have the enemies sorted, There will be a boss and some new weapons that werent in the original games to add more choices in the types of weapons you can use but I will only put about a few weapons since it is only a demo. If anyone wants to make a suggestion feel free but only about the boss or the storyline.Ciao.