FrostyThorn0: I did as you said, and installed Dungeon Hack just straight onto my desktop, instead of the GOG Galaxy Games folder. Interestingly enough, my install does not contain the setup file that you specified (I searched every single folder). And as before, the arrow keys, which I am able to remap to WASD (I always have), are the default controls on a fresh install.
The numpad does nothing on the GOG version of the game, trying both with numlock off and numpad on.
The setup_dungeon_hack_v1.0_(28044).exe is the offline download that is from the GOG website, not GOG galaxy. Not that it should make any difference, as they should install the same files.
Did you also remove the bindings for q, w, e, a, s ,d?
In any case here's the contents of my mapper-0.74-2.map. You should be able to open yours in the Dungeon Hack install folder (use notepad or something similar) and replace the contents.
For me with this setup, upon starting the game wasd will not work. Press 'n' once to toggle the numlock and the controls will then function normally. (numlock has been bound to 'n' in this mapper) 'q' and 'e' rotate left and right respectively.
hand_shutdown "key 290 mod1"
hand_capmouse "key 291 mod1"
hand_fullscr "key 13 mod2"
hand_pause "key 19 mod2"
hand_mapper "key 282 mod1"
hand_speedlock "key 293 mod2"
hand_recwave "key 287 mod1"
hand_caprawmidi "key 289 mod1 mod2"
hand_scrshot "key 286 mod1"
hand_video "key 286 mod1 mod2"
hand_decfskip "key 288 mod1"
hand_incfskip "key 289 mod1"
hand_cycledown "key 292 mod1"
hand_cycleup "key 293 mod1"
hand_caprawopl "key 288 mod1 mod2"
hand_swapimg "key 285 mod1"
key_esc "key 27"
key_f1 "key 282"
key_f2 "key 283"
key_f3 "key 284"
key_f4 "key 285"
key_f5 "key 286"
key_f6 "key 287"
key_f7 "key 288"
key_f8 "key 289"
key_f9 "key 290"
key_f10 "key 291"
key_f11 "key 292"
key_f12 "key 293"
key_grave "key 96"
key_1 "key 49"
key_2 "key 50"
key_3 "key 51"
key_4 "key 52"
key_5 "key 53"
key_6 "key 54"
key_7 "key 55"
key_8 "key 56"
key_9 "key 57"
key_0 "key 48"
key_minus "key 45"
key_equals "key 61"
key_bspace "key 8"
key_tab "key 9"
key_q
key_w
key_e
key_r "key 114"
key_t "key 116"
key_y "key 121"
key_u "key 117"
key_i "key 105"
key_o "key 111"
key_p "key 112"
key_lbracket "key 91"
key_rbracket "key 93"
key_enter "key 13"
key_capslock "key 301"
key_a
key_s
key_d
key_f "key 102"
key_g "key 103"
key_h "key 104"
key_j "key 106"
key_k "key 107"
key_l "key 108"
key_semicolon "key 59"
key_quote "key 39"
key_backslash "key 92"
key_lshift "key 304"
key_lessthan "key 60"
key_z "key 122"
key_x "key 120"
key_c "key 99"
key_v "key 118"
key_b "key 98"
key_n
key_m "key 109"
key_comma "key 44"
key_period "key 46"
key_slash "key 47"
key_rshift "key 303"
key_lctrl "key 306"
key_lalt "key 308"
key_space "key 32"
key_ralt "key 307"
key_rctrl "key 305"
key_printscreen "key 316"
key_scrolllock "key 302"
key_pause "key 19"
key_insert "key 277"
key_home "key 278"
key_pageup "key 280"
key_delete "key 127"
key_end "key 279"
key_pagedown "key 281"
key_up "key 273"
key_left "key 276"
key_down "key 274"
key_right "key 275"
key_numlock "key 110"
key_kp_divide "key 267"
key_kp_multiply "key 268"
key_kp_minus "key 269"
key_kp_7 "key 113"
key_kp_8 "key 119"
key_kp_9 "key 101"
key_kp_plus "key 270"
key_kp_4 "key 97"
key_kp_5 "key 115"
key_kp_6 "key 100"
key_kp_1 "key 257"
key_kp_2 "key 258"
key_kp_3 "key 259"
key_kp_enter "key 271"
key_kp_0 "key 256"
key_kp_period "key 266"
jbutton_0_0 "stick_0 button 0"
jbutton_0_1 "stick_0 button 1"
jaxis_0_1- "stick_0 axis 1 0"
jaxis_0_1+ "stick_0 axis 1 1"
jaxis_0_0- "stick_0 axis 0 0"
jaxis_0_0+ "stick_0 axis 0 1"
jbutton_0_2 "stick_0 button 2"
jbutton_0_3 "stick_0 button 3"
jbutton_1_0
jbutton_1_1
jaxis_0_2- "stick_0 axis 2 0"
jaxis_0_2+ "stick_0 axis 2 1"
jaxis_0_3- "stick_0 axis 3 0"
jaxis_0_3+ "stick_0 axis 3 1"
jaxis_1_0-
jaxis_1_0+
jaxis_1_1-
jaxis_1_1+
jbutton_0_4 "stick_0 button 4"
jbutton_0_5 "stick_0 button 5"
jhat_0_0_0 "stick_0 hat 0 1"
jhat_0_0_3 "stick_0 hat 0 8"
jhat_0_0_2 "stick_0 hat 0 4"
jhat_0_0_1 "stick_0 hat 0 2"
mod_1 "key 306" "key 305"
mod_2 "key 308" "key 307"
mod_3
Hopefully, this will work for you!
If it doesn't, the only other thing I can suggest is changing GOG's included version of DOSBox for a newer one like DOSBox Staging or DOSBox ECE. It would be a long shot, but maybe GOG's version of DOSBox doesn't work properly with your particular setup.
Happy Gaming.