Tachyon Project is fine, but it doesn't have enough meat on its bones and it treads far too much familiar ground. As such, it's relatively difficult to recommend even at its low price point – especially when you consider that the game it mimics is superior. Although Tachyon Project may hold appeal to those that have played the likes of the Geometry Wars to death and are looking for a little bit more, everyone else will be better off seeking their shooty thrills elsewhere.
Astebreed is great fun, and its download price makes it very easy to recommend – it just seems a shame that the game's six stages can be whizzed through in the best part of an afternoon. Without the Score Attack mode, the game would actually feel pretty hollow, but the blast-'em-up's still sure to stir emotions in anyone who had the pleasure of growing up with some of the fantastic titles that inspired it. Just be thankful that this game exists, saving us all a walk to the arcade and countless pockets of change.
Roundabout would probably work better as a PlayStation Vita game, which you could jump into for five minutes while you're riding the tube, bus, or a perpetually rotating limousine. Fortunately, the game was announced for the handheld last year, so hopefully that version still comes to fruition. On the PlayStation 4, there's definitely still fun to be found in this highly stylised game, but the novelty soon wears off if you play it in long bursts.