I am doing a game in blender game engine right now.
blender is very capable
Avoid 3dgame studio, and torque…
both are outdated and overpriced… (I made a joke in poor taste on the 3dgs forum, and they revoked my $200 developers licence in retaliation)
for easy development try:
Crystalspace+CEL+blend2crystal plugin+any other plugins you can find…
Crystalspace is a nice GAME engine… if you follow a few simple rules you can have some very conviveing worlds …
unlike the blender game engine, you can use high end shaders without programming, like:
simple normal maps,
simple water with real time reflections+fallbacks for lame GFX cards.
With the BGE you must write cryptic python scripts for any nice shaders (GLSL shader language knowlage recommended)
Get this, you just build a normal blender material shader, in the blender material GUI, with your normal map, heightmap,gloss/specular map, diffuse map, ETC…
then all you have to do is to let CS2blend know that you want that object in the shadowed render loop… click the check box and that is it!
CS has lots of things you will want for your type of game…
*the terrain system is very nice! adding foliage is a breeze
*particle/emitter systems are very complete, most common things have simple template, or you can start from scratch
*GI lighting is as simple as can be, add your lamps, and it will build a shadow map at runtime for you automagicaly… the edges on the shadow are very realistic and smooth.
Reality factory (you need milkshape or 3ds for this, but has some noobie templates for simple game logic)
irrlicht (can make some nice worlds without code, you will need to script to make/compile a runtime)
sauerbraten (can make a MOD of sauerbraten very easy, makes game maps in real time… great for beginners to learn basic concepts of a 3d shooter)