Remember Lock's Quest? I really enjoyed 5th Cell's 2008 Nintendo DS game, with its lovely story, lovely pixel art style and lovely tower defence gameplay. Now, nine years later, it's being remastered for the current generation.
Tower defence has had such a good run on the internet - and now on downloadable services - that it was only a matter of time before someone bound it to an isometric RPG and stuffed it full of spiky hair and hitpoints. With that matter of time now up, Lock's Quest throws us into the world of archineers - canny builders who erect massive fortifications in minutes and then run around shoring them up while Frankenstein's clockwork robots bash away from the outside.
It's more of a strategy ARPG than tower defence, but the inspiration is clear, and it has the same compelling quality. At the start of most missions you're given a couple of minutes to build walls and lay traps, and then you go into battle mode. Here you take control of the eponymous Lock, and send him running around repairing damage as the forces of the unashamedly evil Lord Agony lay siege. As enemy numbers grow and new units like archers, wizards and flyers present themselves, your build strategy evolves and you salvage materials to make new turrets and traps.
Controls for the build and battle phases differ, but both are well explained and intuitive to boot. Building involves selecting types of wall, turret and trap from a touch-screen selection menu and dragging and dropping them onto a grid that overlays the terrain. You can rotate them by tapping the left shoulder (or switch to the right shoulder if you're left-handed), and scroll the map with the d-pad (or face buttons). This allows you to pinpoint the dark ground that enemies emerge from so that you can adjust your defensive position to fit the scenario.