3 game modes + a level editor:

Single Player Game:

A challenging platform game where you have to make your way to the exit.

Controls:

Arrows = move and jump
Numpad 0 = shoot
Numpad 1...9 = select weapon
Esc = back to menu
F1 = help (for more keys & commands)

Hart Defense:

Two player game where you and a friend have to fight together against the enemies and protect your heart.

Controls:

Player 1
W,A,S,D = move and jump
E = fire
1...8 = select weapon

Player 2
Arrows = move and jump
Numpad 0 = fire
Numpad 1...8 = select weapon
Esc = back to menu
F1 = help (for more keys & commands)

DM maps:

A fighting game for 2 players and you can load an existing or your own map.

Controls:

F2 = load map
The other controls are the same as in Hart defense

Level editor:

Press Enter in the main menu to access the editor. Press F1 to see how to use the editor.

Console commands (press "Home" and put in one of the next commands)
save - save game
load - load game
screensave - Screenshots(*.bmp)
delscores - delete score table

Cheats (press "Home" and put in one of the next cheats)
undead1 = restore your life
iamvenom1 = gives you extra ammo