Lunar Knights
I was one of the crazy people who thought Boktai was cool, in spite of being chained to a rather clumsy physical object (the sun), so in theory a DS spiritual sequel with no solar sensor should be perfect. And on top of having the classical Boktai-style action and upgradeable weapons, it boasts two characters (one of whom has a sword), action-RPG style experience with levelling up, a ... weather system, and sweet animated cutscenes.
Unfortunately, the isometric overhead adventuring that seemed like a good idea four years ago now has its flaws highlighted. There are oversights in this design that should have been worked out as the game series progressed, but it seems largely untouched; things like enemies being hidden from view behind pillars, and awkward shooting angles.
Another thing that irks me is that there are very few stealth elements in this game - you can "whistle" (blow) into the microphone to distract an enemy, but there's no wall-tapping or slow walking to sneak around. I expected more from Mr. Kojima. Nonetheless Lunar Knights has a good deal of fun in it. The two characters (sword-swinging Lucian and gunslinging Aaron) both have a good selection of abilities, since the game is oriented wholly around combat. The space shooter levels for purifying a vampire are ... interesting, and fortunately, not frequent enough to bring the rest of the game down.
Fun fact: you can play the game without it, but, optionally, plug any Boktai cart into the GBA slot and Lunar Knights will read the accursed solar sensor for an extra boost to certain stats.
Progress: Chapter 3