HTML and CSS Reference
Controlling the difficulty of the game
We spawn a new enemy from ime to ime using the ticker loop. We can control the
difficulty by controlling the spawning frequency. The faster the enemies come, the less
ime the player gets to prepare, thus making the game more difficult.
The enemy types also affect the difficulty level of the game. A fast-moving enemy is usually
diicult to handle because the player gets much less ime to prepare for the defense.
Enemies with higher HPs are diicult to handle too. When the enemy takes more ime to be
killed, it wastes more bullets. This means that fewer bullets reach other enemies and those
enemies get more ime to advance without geing hurt.
Let's further discuss on how our game design influences the playing strategy.
The tower defense strategy
This game is a kind of tower defense game where a player builds buildings to defend the
base and defeat the enemy waves. By introducing waves, we've designed the required
strategy to clear the game.
Since the ime before the enemies reach the earth is limited, a player needs to ind the
opimal build order for his/her survival. We will use the unit E to represent energy in the
following strategy analysis. This makes the calculaion easier to read.
Each wave starts at 120E. At the beginning, a player has the following opions:
F Build one satellite (30E) and one castle (80E) with the remaining 10E energy.
Wait for 300 ms for the first energy and then build another satellite and castle.
F Build two satellites (60E) with the remaining 60E energy. Then, we get two energy
bubbles ater 300 ms, resuling in a total of 260E energy. Once this is done, we can
build three castles within a second.
F Build three satellites (90E) with the remaining 30E energy. Then, we get three
energy bubbles almost at once. Now, we have 330E after 300 ms. Once this is done,
we can build four castles (320E).
F Build four satellites (120E) and wait for the 400E energy for half a second. Then,
we can build five castles.