Before you ask: no, Douglas Adams has not come back to life to design a "Hitchiker's Guide" flash game. That's a dream that will have to stay a dream (well, except for this), but don't go away. If you stick around you'll get to enjoy Don't Panic, an excellent defense shooter from Ralph Damiano.
The concept of Don't Panic is simple. You play a king...or, at the very least, someone who is a crown enthusiast, and you must defend your fortress against a mad scientist and his robot minions. This king moves by using the [WASD] keys, just like most kings. Click the left mouse button to fire your weapon at the robotic invaders. To select a certain weapon you'll use the #1-6 keys. All six weapons are unlocked from the start, so don't be afraid to switch to something more powerful early. Finally, if you need some heavy firepower, walk back to your cannon, hit the [spacebar], and you'll be ready to to turn your invaders into craters. If you get overrun by enemies, don't worry too much; you can replay the level with all money you collected during the round.
Naturally, you'll need money to fund your war. Every enemy you defeat will drop some gems which you can gather up by moving your mouse over them. At the end of each level you can visit the store, which is important because you'll need to buy ammunition for your weapons, since only the default gun has unlimited ammo. This can get expensive, so spend your money wisely. You can also purchase reinforcements, AI controlled units that'll help you defend or repair your base. And of course, there's weapon mods; these are items that you can buy to add to your weapons that'll give them a damage boost or help you earn more money. Oh, and if 14 levels aren't enough to get your defense fix, there's also a survival mode.
Analysis: Don't Panic isn't an especially original game, as about every core element can be found elsewhere. However, the quality of Don't Panic is not so easily found in other titles in the genre. Unless defense shooters just aren't a genre you like, then you'll find very little wrong with this one.
Don't Panic does something not enough games do: it doesn't let you fall into a routine. In a lot of a defense games, you can upgrade a weapon and depend on that weapon. In Don't Panic, one weapon alone won't get you through the level. Even if every shot is precise, you're going to run out of ammo. Then, you have to be ready to fight with a new weapon and that one won't last. You have to be ready to adjust quickly and that's what makes the game so fun and addictive. The importance of ammo makes the upgrade screen not just a screen where you click to get stronger, but a place to plan for the current and future battles. You need ammo, but reinforcements and mods could help you save ammo. Even in between rounds, Don't Panic keeps you on your toes. But, even if things get rough for you, the game is on your side. Being able to retry with all the money you earned during the round and all of your health restored gives you incentive to keep playing and helps you along.
The rounds are well designed. You're constantly being attacked, so even at the start of a level there's an urgency. It's not uncommon to be attacking a line of armored enemies that are drawing uncomfortably close to your base and then notice a group of small quick units getting even closer on the other side of the screen. These situations give the game a charge, and even if your base is healthy you can get sucked into trying to stop every last robot. A game like Don't Panic could get repetitive, even with only 14 levels, but the excitement of close-calls and too-close-for-comfort scenarios will make you want to keep playing.
Don't Panic isn't a flashy game, but it looks good. The game is filled with bright colors and your king and his subjects are odd looking creatures. It's a bit of a shame that you mostly see these wonderful creatures from the back or side as they fill up the roof of your fortress as reinforcements. Don't Panic is a well-designed game on all fronts. Ralph Damiano has made an incredibly fun and exciting game that doesn't let you rest on your laurels, but also takes measures to make sure you're still enjoying it. Each level can get you as excited as the one before.