updated help

public/help.html

@@ -47,6 +47,22 @@
 						A timed game only lasts for 30 seconds, and the goal is to get as high a score as possible.
 					</p>
 				</section>
+				<section>
+					<h3>Survival</h3>
+					<p>
+						In survival mode, the playfield doesn't loop, fruits don't spawn, and you can't win.<br>
+						This modes get progressively harder, with speed increases, and snake growth.<br>
+						At first, this process is slow, but it gets faster with time.
+					</p>
+				</section>
+				<section>
+					<h3>Puzzle mode</h3>
+					<p>
+						In puzzle mode, time doesn't flow until you move.<br>
+						Weird tiles make their debut, like portals, keys, etc.<br>
+						Your goal is to get the fruits in as little moves as you can.
+					</p>
+				</section>
 			</article>
 			<article>
 				<h2>Tiles</h2>
@@ -58,6 +74,8 @@
 					<li><em>Oil</em> is flammable and will periodically catch on fire, which will kill you. It is otherwise perfectly safe</li>
 					<li><em>Super fruits</em> give you 10 points, and sometimes spawn in arcade mode</li>
 					<li><em>Decaying fruits</em> give you 5 points and sometimes spawn in arcade mode, but they also decay after 2 seconds and disappear</li>
+					<li><em>Portals</em> teleport you to the corresponding portal</li>
+					<li><em>Keys</em> make <em>Doors</em> disappear</li>
 				</ul>
 			</article>
 		</main>