Space Run has got to be one of the least tower defence-y tower defence games in my Steam library. It has more in common with FTL than with most other games in its genre: your aim as Captain (and certified space-postman) Buck Mann is to fly your ship as quickly as possible from collection point to delivery point, micro-managing your resources and defences in real-time to deal with the various threats that emerge during your journey. No matter the cargo - crates, nuclear fuel, or passengers - Buck Mann offers the speediest journey through what I can only assume must be the most dangerous possible routes in the galaxy.
There are three things that I really appreciate every time I return to Space Run. First: I appreciate the complete lack of any attempt to marry the mechanics with the story. Your ship in Space Run is made up of hex-shaped modules that fit together, and each hex is a potential building spot for anything you like: turrets, shield generators, missile launchers, power generators, and various other implements designed to keep your cargo from turning into a silent fireball in the depths of space.
But at the end of each mission, all that stuff that you spent hundreds of credits constructing on the fly (adjusted for inflation, that's likely something along the lines of $723,000,000,000.00) is removed, and you're left with an empty hull for the next mission. I don't know about you, but I'd have thought it would save time and money if you, oh I don't know, maybe kept some of those turrets from the last mission instead of starting from scratch again? Buck Mann probably has whole containers filled with discarded multi-million-dollar defence systems somewhere on his ship.
The second thing I appreciate (and this is a real appreciation this time, not just an excuse to rant) is how the game always gives you precise information about incoming threats before they arrive. You're given details of the incoming threat, their number, the direction from which they'll emerge, and how many seconds you have until they arrive. That might sound like a pretty big advantage, but you really need that time to prepare, to swing your turrets round to point in the right directions, to recycle old defences so you have enough scrap to build new ones in the correct locations... It's a fantastic tension-builder, displaying a very Hitchcockian awareness of the value of suspense over surprise.
And the third and final appreciation I have for Space Run is the amazingly cheesy Galaxy Quest-esque victory music that plays upon completion of every mission. Have you ever rolled your eyes while pumping your fist in the air? No? Then play Space Run and get back to me.