Experienced Multiplayer Fish-Shooting Game Developer Needed for Real-Money Sweepstakes Platform

We are seeking an experienced individual developer to build a reusable fish-shooting game platform for our sweepstakes gaming business. This is a real-money-value sweepstakes project, not a play-money arcade game or simple demo. Players use Gold Coins for entertainment and Sweepstakes Coins within our sweepstakes model. Eligible Sweepstakes Coins may be redeemed for real-world prizes. We want six distinct branded game experiences built on one secure, reusable platform—not six unrelated codebases. The platform must support multiplayer gameplay, wallet/API integration, game math, security, configuration, and future expansion. We are seeking a long-term development partner because we plan to continue adding games, themes, features, and improvements to our library. Important: Do not apply unless you have directly relevant experience and can provide examples of fish-shooting games, real-time multiplayer systems, or comparable secure game/API integrations. Generic proposals will not be considered. Existing Platform and APIs Our company already manages player accounts, wallet balances, purchases, eligibility, and redemptions. We also have APIs for authentication, wallet and balance data, transactions, game sessions, results, and related functions. The developer will integrate with our existing APIs rather than build a separate wallet or balance system. Our platform wallet must remain the source of truth, and the game must not hold, control, or pay out player funds directly. We can provide API documentation and staging access. The developer must clearly explain the proposed integration, transaction flow, error handling, and required information. Required Platform The completed platform must include real-time multiplayer with actual human players; server-authoritative rooms, sessions, gameplay, results, and RNG; synchronized players, fish, weapons, shots, hits, captures, jackpots, and prize displays; multiple functional cannons with different shot, power, bet, or gameplay characteristics; multiple bet levels; multiple rooms or tables; responsive web and mobile-browser support; and PWA support. It must also handle disconnects, reconnects, failed or incomplete rounds, duplicate requests, transaction reconciliation, server-side payout resolution, and protection against client-side manipulation. No simulated players may be presented as real human players. Fish and NPC behavior may be scripted or deterministic. Game Math and RTP RTP, probability, volatility, jackpots, payout exposure, and secure game-result handling are critical requirements. The developer must provide a documented approach for calculating, simulating, validating, and controlling the game math. Expected RTP and payout distribution must be demonstrated through simulation or comparable testing before production development begins. All financial, wagering, reward, and game-result logic must remain server-side. CMS, Branding, and Assets The completed platform should include practical administrative controls for managing game themes, branding, fish and weapon settings, bet levels, RTP or volatility settings, jackpots, payout limits, exposure controls, game availability, and maintenance mode. Please explain how permissions, approvals, audit logs, and rollback would be handled. The six games must have distinct presentation, including differences in names, logos, colors, UI, environments, backgrounds, fish, weapons, animations, effects, sounds, prize displays, and gameplay presentation. Assets must be original, supplied by our company, or properly licensed. The visual quality and asset detail must be reasonably comparable to the reference example shared privately. Clearly identify placeholder assets, licensing restrictions, dependencies, and additional costs. Technology and Future Platforms We are open to the technology, framework, white-label solution, or architecture you recommend. Explain your recommendation, customization limits, performance, security, ownership, licensing, third-party dependencies, recurring costs, and maintenance requirements. Initial targets are web, mobile browsers, and PWA. The architecture should prepare us for future iOS and Android applications through Apple App Store and Google Play. Identify any relevant technical, legal, sweepstakes, payment, or app-store restrictions. Budget and POC Our maximum total project budget is $6,000. The project will begin with a separate paid, fixed-price technical validation POC. The full project is not guaranteed and will only be considered after the POC is completed, delivered, and accepted. The POC must include: * A working browser-based underwater prototype * Basic fish-shooting gameplay * Three functional cannons * Multiple fish with different values or difficulty levels * A live multiplayer room with at least two real human players playing simultaneously * Synchronized players, cannons, shots, fish, hits, captures, and results * Server-authoritative gameplay and secure server-side results * Preliminary working game math and RTP simulation * Test, mock, or staging wallet/API transaction flow * Unique round and transaction IDs * Failed, rolled-back, duplicate, disconnected, and incomplete transaction handling * Basic client-manipulation protection * Desktop and mobile-browser functionality * Representative assets comparable to the private reference example The POC must include the working prototype, source code, server/backend code, private repository access, setup/testing instructions, architecture/API documentation, math/simulation documentation, known limitations, recommended next steps, and all third-party services, dependencies, assets, licenses, and recurring costs. No production credentials, live wallet access, payment information, live player data, or real player funds will be provided during the POC. The POC must be submitted through Upwork by the agreed deadline. Incomplete, nonfunctional, materially different, copied, unauthorized, or undocumented work will not be considered complete. Reasonable corrections within the agreed scope must be completed at no additional cost. No additional work, subscriptions, assets, or expenses may be incurred without our company’s prior written approval. Ownership and Support We require full source-code access, a private repository, documentation, deployment instructions, API and game-math documentation, clearly defined ownership or licensing rights, no hidden dependencies, no unauthorized assets, and a post-launch bug-fix warranty. All repositories, hosting accounts, databases, domains, API keys, and third-party services must be created under or transferred to our company’s ownership whenever applicable. The developer must be flexible and responsive to critical production issues within a reasonable timeframe. Proposal Requirements Please provide: 1. Fish-shooting games you personally built 2. Real-time multiplayer games you personally built 3. Your exact role in each project 4. Live demos or videos whenever possible 5. Your recommended technology and architecture 6. What you can realistically deliver within the $6,000 budget 7. Your proposed milestone structure, pricing, and timeline 8. POC deliverables and timeline 9. Your RTP, game-math, RNG, and simulation approach 10. Your wallet/API and failed-transaction approach 11. Expected player capacity and load-testing plan 12. Estimated hosting, licensing, and recurring costs 13. Your weekly availability, location, and time zone 14. Post-launch support and warranty terms 15. Whether you will personally complete the work or use subcontractors Please do not apply if you cannot demonstrate relevant fish-shooting or real-time multiplayer experience, cannot provide comparable examples, are unwilling to provide source-code access, cannot work within the stated budget, or are not willing to begin with the technical validation POC. We are looking for a qualified long-term partner who understands that this is not simply six visual reskins. We want one secure, documented, source-owned platform with six distinct branded experiences that can grow with our business.