I won't beat around the bush; La-Mulana is a straight ten out of ten game, one of the best I've ever played; a seemingly neverending odyssey of ideas, beautiful graphics and sound and a constant infusion of love for retro gaming inhabiting every screen.
It's a game that comes in two flavours, but I'm going to focus on the 2012 remake here as a) it's a friendlier, more enjoyable experience and b) has just been released along with La-Mulana 2 for modern systems. It's arguable that the remake slightly dilutes the esoteric excellence of the MSX love-fest that is the original freeware La-Mulana, but the trade-off is a much more accessible and enjoyable game that almost anyone can get into.
Okay, maybe that's a stretch. La-Mulana is one of the most difficult games around, a nightmare of puzzling confusion that absolutely 100% requires that you take notes; by the end you'll have multiple pages of scrawled reminders as though you're playing Myst or something. Yet, you're eased into the experience by a fairly gentle learning curve, considering. The first four areas you'll generally encounter are all eminently solvable, with their puzzles well-hinted by stone tablets and environmental cues. Later, though, you'll be made to suffer, with conundrums that span the entire enormous game world. Beating this game without using a guide isn't just impressive, it's near-impossible.
There are also plenty of mean traps, but you'll come to gain a sixth sense for where they're going to spring. Additionally, it's not a game that's difficult to get around in. You gain an artifact called the Holy Grail early on - far from granting immortality, it allows you to warp between "Grail Tablets", essentially warp points you activate as you explore. Without this the game would be a nightmare of backtracking, and some of the little traps would be totally inescapable. The Holy Grail effectively turns the unfair game into a fair one, and because of it La-Mulana never descends into total hostility. It's one of those games where if you're stuck, there's probably something else you can do and definitely a hint lying around that you may have missed.
Movement and control could be a sticking point for some - your character, Lemeza, has that sort of sticky Castlevania-esque movement where once a jump is committed to it cannot be reversed. To further the 'Vania similarity, he even uses a whip as his initial weapon, but as you play through you'll unlock more means of attack, including limited-use subweapons like shurikens and caltrops. It'll be up to you to find the best, most practical places to use them.
Thanks to a consistent drip-feed of cool new stuff, La-Mulana is always rewarding. Even if you do resort to a guide, it's a treat for the senses with its beautiful pixel art and superb soundtrack. It's available on pretty much everything now (even the Vita, which has the most complete version with its added bestiary), so you have no real excuse for not giving this masterpiece a go. Unless you just don't feel like it, obviously, which I can't really argue with.