Welcome to Willy's Fun Park! is the fifth JSW game released by Hervé Ast, and the third one using the JSW64 game engine. Its launch in July 2025 marked Hervé's triumphant return to the JSW scene after 18 years of absence. The game was released in four language versions: English, French, Polish and Spanish.

Welcome to Willy's Fun Park! is set in an amusement park of which Willy apparently is the owner, but he still needs to clean it or else Maria will not let him enter the parking lot where his vehicle is parked. The game features 64 brand-new rooms with places typical of a funfair, such as an impressive rollercoaster, a Ferris Wheel, a haunted house, a hall of mirrors, a maze and bumper cars. There is also a pirate ship, a casino, activities such as archery and hook-a-duck and places with food and souvernirs. Some characters that are well-known from Hervé's previous games, such as Yeti or the extraterrestrials, make an appearance, too.

The title-screen music ("Sobre las olas" or "Over the Waves" waltz by Juventino Rosas) and the in-game music ("Itsy Bitsy Teenie Weenie Yellow Polka Dot Bikini" by Paul Vance and Lee Pockriss, first performed by Brian Hyland) was coded by Daniel Gromann, who also contributed some other final enhancements to Hervé's beautifully atmospheric game.

Welcome to Willy's Fun Park! features:

- 256 items to collect;

- Complex graphics and interesting challenges based on features provided by

the JSW64 game engine, such as switches, droplets and trampolines;

- A moderate level of difficulty, which won't put off a novice and won't bore an expert;

- Custom-coded title-screen and in-game tunes.