I've been having this game in my mind and I wanna make a game inspired by it, I'm just not sure if this is a DOS game. thanks in advance for the replies.

That's a Windows game, according to MobyGames: https://www.mobygames.com/game/windows/forestia. 

You can probably still make something influenced by it, just be mindful of what limitations a DOS game would have. You might want to take a look at late DOS adventure games. It seems to me that its a bit too high-res to be DOS