You can redefine the keyboard keys (recommended) or use a Kempston joystick. Note that you will need 2 fire keys, one for missiles and one for bombs. Unless you have a compatible pad with more that one fire buttons, you can use the keyboard key for bomb along the joystick control.
I tried hard to retain the original vibe of the game, so I decided to keep the colour count low, respecting much of the original Spectrum graphics.
Moving your vertical take off aircraft around the screen is smooth, since you are no longer confined to the 8px (character) movement of the original game. Scrolling is smooth as well, but remember: the next may able to scroll very fast but that does not mean you need to go that fast! In fact, fuel consumption is maximum at slowest and fastest speeds, and you need to keep an eye on that tank if you want to finish the missions, that is raiding and bombarding the 4 evil Cxxxxdore empire cities! Watch out for flak, gathering too much damage will destroy your plane, and avoid the enemy aircraft as well. Plus, remember, if you bomb your own aircraft carrier...
Jump on your ZX Harrier, take off, and gain as much points as you can on these 4 missions!