[nerv_]

да и есть соображения по поводу избавления от тормозов (ФПС ужасен)

ну а что вы хотели? Подобные конструкции не есть гуд

space.innerHTML +=
	 '<div id="ship" style="left:' + ship.x + 'px;bottom:' + ship.y + 'px">\
		<table border="0" cellspacing="0" cellpadding="0">\
		   <tr>\
			  <td></td>\
			  <td class="top">\
				 <div class="fire_l" style="display: ' + ship.fire_l + ';"></div>\
			  </td>\
			  <td rowspan="2" style="vertical-align: bottom; height: 36px;">\
				 <div id="body"></div>\
			  </td>\
			  <td class="top">\
				 <div class="fire_r" style="display: ' + ship.fire_r + ';"></div>\
			  </td>\
			  <td></td>\
		   </tr>\
		   <tr>\
			  <td rowspan="2" class="ship_left">\
				 <div id="left_engine_1" style="display: ' + ship.engine_l_1 + ';"></div>\
				 <div id="left_engine_2" style="display: ' + ship.engine_l_2 + ';"></div>\
			  </td>\
			  <td rowspan="2" style="vertical-align:bottom;">\
				 <div id="body_left"></div>\
			  </td>\
			  <td rowspan="2" style="vertical-align:bottom;">\
				 <div id="body_right"></div>\
			  </td>\
			  <td class="ship_right" rowspan="2">\
				 <div id="right_engine_1" style="display: ' + ship.engine_r_1 + ';"></div>\
				 <div id="right_engine_2" style="display: ' + ship.engine_r_2 + ';"></div>\
			  </td>\
		   </tr>\
		   <tr>\
			  <td class="ship_bottom" rowspan="2">\
				 <div id="engine_1" style="display: ' + ship.engine_1 + ';"></div>\
				 <div id="engine_2" style="display: ' + ship.engine_2 + ';"></div>\
				 <div id="main_engine_1" style="display: ' + ship.engine_m_1 + ';"></div>\
				 <div id="main_engine_2" style="display: ' + ship.engine_m_2 + ';"></div>\
			  </td>\
		   </tr>\
		   <tr>\
			  <td></td>\
			  <td class="ship_bottom_left">\
				 <div id="left_engine_f_1" style="display: ' + ship.left_engine_f_1 + ';"></div>\
				 <div id="left_engine_f_2" style="display: ' + ship.left_engine_f_2 + ';"></div>\
			  </td>\
			  <td class="ship_bottom_right">\
				 <div id="right_engine_f_1" style="display: ' + ship.right_engine_f_1 + ';"></div>\
				 <div id="right_engine_f_2" style="display: ' + ship.right_engine_f_2 + ';"></div>\
			  </td>\
			  <td></td>\
		   </tr>\
		</table>\
	 </div>';
}

это можно сократить/оптимизировать

if(ship.engine_1 == 'block'){
	 ship.engine_1 = 'none';
	 ship.engine_2 = 'block';
  }else{
	 ship.engine_2 = 'none';
	 ship.engine_1 = 'block';
  }
}else{
  ship.engine_1 = 'none';
  ship.engine_2 = 'none';
}

  if(ship.engine_m == true){
	 if(ship.engine_m_1 == 'block'){
		ship.engine_m_1 = 'none';
		ship.engine_m_2 = 'block';
	 }else{
		ship.engine_m_2 = 'none';
		ship.engine_m_1 = 'block';
	 }
  }else{
	 ship.engine_m_1 = 'none';
	 ship.engine_m_2 = 'none';
  }

  if(ship.engine_r == true){
	 if(ship.engine_r_1 == 'block'){
		ship.engine_r_1 = 'none';
		ship.engine_r_2 = 'block';
	 }else{
		ship.engine_r_2 = 'none';
		ship.engine_r_1 = 'block';
	 }
  }else{
	 ship.engine_r_1 = 'none';
	 ship.engine_r_2 = 'none';
  }

  if(ship.engine_l == true){
	 if(ship.engine_l_1 == 'block'){
		ship.engine_l_1 = 'none';
		ship.engine_l_2 = 'block';
	 }else{
		ship.engine_l_2 = 'none';
		ship.engine_l_1 = 'block';
	 }
  }else{
	 ship.engine_l_1 = 'none';
	 ship.engine_l_2 = 'none';
  }

  if(ship.left_engine_f == true){
	 if(ship.left_engine_f_1 == 'block'){
		ship.left_engine_f_1 = 'none';
		ship.left_engine_f_2 = 'block';
	 }else{
		ship.left_engine_f_2 = 'none';
		ship.left_engine_f_1 = 'block';
	 }
  }else{
	 ship.left_engine_f_1 = 'none';
	 ship.left_engine_f_2 = 'none';
  }

  if(ship.right_engine_f == true){
	 if(ship.right_engine_f_1 == 'block'){
		ship.right_engine_f_1 = 'none';
		ship.right_engine_f_2 = 'block';
	 }else{
		ship.right_engine_f_2 = 'none';
		ship.right_engine_f_1 = 'block';
	 }
  }else{
	 ship.right_engine_f_1 = 'none';
	 ship.right_engine_f_2 = 'none';
  }

  if(ship.fire == true){
	 if(ship.fire_l == 'block'){
		ship.fire_l = 'none';
			ship.fire_r = 'block';
		 }else{
			ship.fire_r = 'none';
			ship.fire_l = 'block';
		 }
  }else{
	 ship.fire_r = 'none';
		 ship.fire_l = 'none';
  }

В целом (личное мое впечатление) мало ООП