I don't really use only one engine; i use many engines, programs, software to make my games.
YES. it will take you long time to make a game, Believe it or not i always wanted to do my own games,
My first game was back in 2009 and it sucked lol. Didn't even release then i started working on some programs and trying all engines which gave me more experience.
Finally i made my game [REC] Shutter in 2010 but it was different and took place in a mansion, then in 2012 i improved and released my first game.
Again, it does take time to create a game as i used many different engines like Unity, Torque3D, 2D, 3DFactory, TGC etc and not only engines, you will need to do graphics, textures, scripting, coding, modeling in games.
At the moment i create my 3D games using Unity3D it's a great engine.
Using software such as Paint.Net, Java scripting, C# and C+ for scripting and graphics/Edits.
For Wasteland Online, i use a 2D engine and it's hard.
If you want to make a simple game it's 'okey', but if you want to go a little advance it takes hell lot of time.
As i posted in some threads that i am still learning source edits and such, and they are very hard.
I'm using MMORPG MAKER something like PALO mentioned, Although with the game engine itself you wont do anything
so i use VB to edit the codes and got a friend to help me out with them since I'm beginner at sources.
I Also use paint.net to create GUIs and HUDs and sound software to create the ambiance.
Despite the time, I enjoy creating them and getting feedbacks