One of the remarkable things about the first three games in the Cally's Caves series of action-platformers is in how far they came in a relatively short time. The first game is quite primitive compared to the third, but they released only a couple of years apart. The thing about gains like that is that they rarely scale in a linear fashion. Cally's Caves 3 [Free] was an outstanding accomplishment for an indie game, presenting something that wouldn't have been terribly out of place as a retail release on a dedicated handheld. There's really only so much more Cally's Caves 4 [Free] could realistically be expected to do to top that. True to that, this is more or less another helping of the high-quality action found in Cally's Caves 3. For whatever it lacks in novelty, however, it makes up for by burying you in quantity. If you're new to this series, the Cally's Caves games are action-platformers in the vein of something like Mega Man X. You play as a little girl named Cally who starts off with little more than a pea-shooter and a sword but eventually amass a rather large arsenal of projectile weapons. These weapons are upgraded in a fashion similar to Sony's Ratchet & Clank series. The more you use them, the more powerful they become, even changing shape and function at certain intervals. Cally can also level up herself, increasing her health stats among other bonuses. You can also upgrade your character using the gobs of coins dropped by enemies and found in treasure boxe...