Be patient, game takes a minute to load (no pre-loader). Like the original game, you are trapped in a maze of sorts and have to fight your way through enemies and solve puzzles to get out.
By pressing the arrow keys move around and search the rooms. To kill enemies, press 'z' to set a bomb and press 'z' again to detonate it. Collect coins, keys, and items to help you find your way out. Press 'm' to view the menu and 'm' again to close it. While viewing the menu press left or right arrow keys to view submenus. Press 'a' in facing doors to check them or on top of blue ground buttons.
Most enemies appear randomly, so don't rush into a room. You never know what lies ahead. Everything pretty much happens for a reason - take note of things. Life packs always stay where they were left unless you pick one up. So use them in moderation and take note of where they are.
Go out of a room and then back in to have enemies appear in a different place. If you get trapped between a couple of enemies and/or a wall and enemies then you have to keep using a bomb to escape, even though it hurts you too.
Blue ground buttons do random things. For some puzzles they will reset the position of things and where you are. Press 'a' when you are standing on them.
Moving and navigating around - arrow keys
Action and checking - 'a' key
Show/hide menu, pause - 'm' key
Toggle options - space
Set / detonate bomb - 'z'