Haven't done a tutorial in awhile since the last game I had with rewards as QUBE, and that one was easy and everyone was talking about how to do em. Tonight, however, I bring you a rewards tutorial for
Dark Void Zero (I did em all in the first day)!
Bookworm
£0.10
This is the ONLY achievement you can get early on, so if you're only buying the game so you can make credits on it, and you're not willing to put some effort into getting the last two, you may want to think twice, because the other two achievements both require beating the game (it's a short game, but still). To get Bookworm you simply have to collect all the journals in the first level. They're all easy shown on this map (note that the last one is in a secret area).
All My Enemies
£0.25
Not much to say here. Kill one of each enemy type. Unfortunately the final boss factors into this, so you'll have to beat the game to get this one.
L337 Sk1llz!!
£0.50
Okay, now for the hard stuff. There's not really an explanation I can give you on this one, since you have to beat the game on hard mode (which is by no means easy), but I can offer a few tips and point you in the direction of a collection of video playthroughs that can help you at least know where to go and what to expect. I'd highly recommend watching the playthrough videos of the boss battles before jumping into them, so you know what's in store for you.
Realize that while this game saves by letting you retry the level you're on over again if you die, it also saves the amount of lives you had at the end of the previous level. I believe this means that if you have 0 lives and beat level 1, you'll come into level 2 having 0 lives, and if you die and continue, you will still have those 0 lives. On the flipside, if you come into level 2 with 5 lives, you should have 5 lives every time you "continue" from the main menu. This means you need to make sure you're not losing lives when you shouldn't be. Level 1 is pretty easy, so aim to lose NO lives on level 1, pick up the 1up (it's above the start area, accessible once you get a rocket pack), and collect every orb to get another life. This should help you immensely going forward. You should aim to do the same thing on level 2, though it's harder, because it's nothing compared to the difficulty level of level 3, and you're going to need lives to burn going forward.
Hopefully you can get to the final boss with a lot of lives in your pocket. He's not easy at all. I was able to get through level 1 and 2 with no deaths, picking up all the 1ups and orbs, so when I was able to get through level 3 without dying, I had 12 lives to face the final boss. I'm damn sure glad I did, because he smoked me 4 times. He's tough. There's so much going on in the final battle that you're going to really have to keep your cool and clear the screen of enemies and mines quickly so you can focus on dodging the boss's attacks. Things get frantic at the end, so just keep your cool and aim true.
Anyways, here's a link to playthroughs of each level. They're helpful, so use them:
http://videos.neoseeker.com/walkthroughs/182646-stage_1valley_of_doom/
Really fun game, and an awesome throwback to oldschool stuff. It's not really a platformer in the true sense of the word, since you're flying/hovering most of the time, but it's similar to Contra and easy enough to pick up. I won't be playing it anymore, since I beat the game on hard and am not interested in doing that again, but it was a fun 1-2 hour experience that got my blood pumping a few times. Definitely worth buying with credit to make even more credit back while playing a fun, challenging game.