Now here's one dedicated developer. Jamie Woodhouse designed Qwak for the BBC Micro some twenty years ago. Since then it was ported to the Amiga by Team 17 and then to the GBA by Woodhouse himself. He's just recently released an updated version for the PC and you can download a demo right now.
Qwak's longevity isn't simply due to its creator's obsession. Woodhouse's original design has something of a timeless feel, mixing simple platforming, points scoring and collectibles into a highly addictive combination. Fruit and gems give you points, keys unlock doors and chests, umbrellas release more fruit and gems, but can also boost your jumping ability, while eggs provide ammo to take out the enemies.
Playing out over a series of single screens, it provides a challenge that isn't too punishing, and its rewarding enough to keep you coming back for one more go. Thoroughly recommended!