Mutagen is a Mid-Weight and Upbeat.

About Mutagen, from BoardGameGeek:

As mining activities intensified in the twilight years of the industrial revolution, competition for natural resources grew fierce and industrialists burrowed themselves deeper and deeper into the sodden depths of the earth. One mining operation dug deeper than any other, and the events that followed this endeavour have become the stuff of myth and legend. What little information is known about the venture centres on the discovery of a new and powerful element, an element known simply as ‘The Great Shard'. The Great Shard's mystical properties not only accelerated the industrial revolution dramatically, but also altered the world around it, spawning creatures and phenomena that defied every natural law imaginable. The world would never be the same. Soon, the mad industrialist known only as ‘the Keeper' had learned to control the power of the Great Shard. Their lust for progress extended beyond the industrial world through which they had gained their power, and morphed into an obsession with biogenetic modifications. People who indulged in this practice of self mutation became known as the Mutagen. Now, many years later, the Keeper of the Shard is nearing the end of his unnaturally extended life, and you are one of four Mutagen in the running to take over their position of power. The Keeper will be observing your every move, and will choose only one successor before he draws his final breath. Mutagen is a customisable worker placement game set in a 1920s biopunk universe. Each player has four workers that each react differently to the areas they are placed in. Each time a player places a worker, they will activate that location's action, plus an additional action determined by the worker's colour. Players can unlock the full potential of biological upgrades, by infusing their workers with biological upgrades that will grant them a decisive edge over their opponents. Each worker location has been forever transformed by vast bio-enhanced changes. Collect elements from the floating cities and use them in various ways. Trade them for objective cards, establish dominance over particular elements through strategic investments, or harness their energy to upgrade your airship. With each move, you accumulate points, driving you closer to victory at different stages of the game. The player who has best harnessed the newfound powers of this biopunk universe, and used them to collect the most amount of points after four years (rounds) will win the game. -description from the publisher