Saw your post on @Curie @brandonsadventur and I'm an indie dev as well, it's very difficult to get exposure when you're just starting out so I've been even more pessimistic than you and I'd be thrilled to get 500 sales and I've gone and developed a full platformer with 20 levels.
Got to say this is probably one of the most useful posts I've seen on steemit for me. You always hear about these huge successes like stick figure and so on which get 1 million sales but never anything about what the small indie devs make.
Have you perhaps considered that it might be a good idea to throw some free content updates? This is something that I have planned to keep interest going in my game and it will also show people that you're not some scammy dev looking to put in loot boxes and aren't just posting up a game to make easy money and rip them off.
Gamers love free content updates of substance, they hate paid DLC, probably one of the best tips I can think of to keep your game going.
That's an interesting thought - I've batted around the idea of making new levels or other game types, or maybe even some stat counters that measure kill ratios per level and overall. Some people have asked about customizing their ships which wouldn't be too hard to add in either.