[Guest reviewer Colin Brown profiles each game in the Winter Bundle available now on IndieGames' co-created site Indie Royale.]

After a break from the last bundle, the traditional obligatory arcade shooter returns to the Indie Royale line-up, albeit with something a little different this time. Leave Home, from qrth-phyl developer Hermit Games, definitely hits all of the usual shooter beats; it's got cool, neon graphics, plenty of lovely explosions and a thumpy techno soundtrack that certainly holds its own against the best examples of the genre. However, Leave Home has one very critical feature that really impressed me and that I just have to completely gush over. The overall game is great, sure, but what Leave Home truly excels at is adaptability.

You see, the central mechanic of the side scrolling shoot-em-up is anger. Blowing up enemies just makes your ship angrier. Collecting blue chips is just enraging for some reason. Both of these actions starts to tint your ship with the angriest shade of orange, allowing for better scores. But while most games would spin this into a score multiplier mechanic or a way of souping up your weapon's effectiveness, Leave Home goes with a much more satisfying route in the form of adaptive difficulty. It's rather simple--the angrier you are, the harder the game is--but in practice it becomes very rewarding.

When I say adaptive difficulty, I truly mean it. Each of the game's six short zones is designed to be tuned to the slightest change in anger, drastically impacting the number of enemies, bullets and bonus chips you come across. Sure it's harder, but more enemies means more scoring opportunities so playing at the highest difficulty possible is the goal. There are no lives or game over mechanics in Leave Home, as a respawn simply lowers your anger by a slight degree and therefore loses scoring potential. I really can't overstate just how well the difficulty is tuned. Two games I played back to back ended with a score difference of about ten thousand points, but the actual set-pieces themselves felt completely different and not in a random, procedural sense. The segments are well balanced in a much more carefully designed sense, making the game an impressive example of shooter design.

The game is quite short, of course, clocking in at a set time limit of five minutes a pop. But the excellent use of adaptive difficulty really lends itself to playing Leave Home over and over, and the breakdown of your relative difficulty at the end works great for identifying which zones give you the most trouble. Better still is the bonuses, like an absolutely batty mode that keeps the game at the highest possible difficulty throughout. While Leave Home certainly does the whole shoot-em-up thing quite well, the excellent care that went into the adaptive set pieces proves to be quite an impressive example of game design.

[Hamlet, Greed Corp, Bit.Trip Runner, Conquest of Elysium 3, Leave Home, and They Breathe are available in the Winter Bundle now at Indie Royale.]