once you get a shield on the mothership (or any level for that matter), just crash into as many ships as you can. it's insta kill for all ships, and since the shield is based on time, not hits, it's great for swarms.
i'm assuming that there is an original deathworld, presumably not in space. if so, i'm surprised that there isn't any sort of menu interface sort of thing (i don't mean to be mean, i'm just giving my opinion). i wasn't interested enough to spend more than 5 minutes on level 5, so i don't know if there are any more levels, but it would be nice if there were more levels and the if difficulty went up gradually. 2/5 since it kept me mildly occupied enough to write this review
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