RPG Codex has a review for this game, link: http://www.rpgcodex.net/content.php?id=9390
The like it very much, a quote about its up and downs:
The game departs from the M&M formula where it matters the most, the overworld exploration. Additionally, it has quite a few flaws in its combat system. But it also preserves and improves core M&M tenets. The character system, the dungeons, the puzzles, the Relics, and yes, even many aspects of exploration have been lovingly recreated to please fans of the series, but also improved - something that the old series excelled at doing in almost every new iteration.
And a quote from the conclusion:
The final verdict should be obvious by now: MMXL is a must-buy and a must-play. Limbic did a superlative job in bringing together many beloved elements from the series, improving where they could and not dumbing down where it matters. The flaws are immaterial in the grand scheme of things; Limbic have proven they can make a real (and good!) M&M game, and they have certainly proven that they can make an excellent turn-based tile-based blobber with all the joyful gameplay elements that entails.
I have been on the fence if I should buy this game, but it seems I might have to do so