I've been enjoying Serious Sam for quite some time now, adoring the balance and the way enemies are designed, in terms of gameplay. However, having played through the first half of TFE for about 1000 times now, I started asking myself if there is any mod, or at least a map pack, that would drastically increase the difficulty. Would be even greater if it's not just x2 enemies, for example, but x2 enemies + added extra enemies of other types.
I didn't mention that I prefer the classical TFE version, since I have some issues with shooting while strafing in Revolutions, writing here, since this community is probably much more active. Not sure how to properly search for this stuff anyway, I've only managed to find mods for extra skins and sounds.
In case such mods don't exist, I would appreciate some info to help me make such mode myself. I am a programmer, yet I have never touched neither game development, or modding.