Scars of the Wounded Prey just wasn't hard enough. So this wad outdoes it in every aspect. Jumping and crouching required. Choice of "Tough" and "Slaughter!" flavours. Picking Slaughter! will almost definitely get you owned at some point. Try with a friend, then you can dish out (and take) twice as much pain!
Credits:
id Software (Doom); Randy Heit and other contributors (ZDoom); CodeImp (DB); Csabo (XWE); Microsoft (Paint, Sound Recorder); Team17 (StuntGP soundtrack)